This post is not intended to be, in any way, partisan, and I will, instead, try to give an objective view on the performance of the speakers. My own political persuasion will not affect this review and I will, instead, try to rate the speakers on how persuasive they are to the undecided voter rather than whether or not I personally agree with their points.
Audience view
Firstly a measure of how the BBC audience viewed the speakers. It was suggested that the audience was selected by an independent polling company, obviously I am unable to verify the veracity of this so I suggest these results be taken with a healthy but not paranoid level of gentle skeptism.
The above chart is a quantitative perspective on how the speakers performed in the eyes of the BBC audience. Muted applauses (where individual claps were clearly evident) were awarded 0.5 points, clear audible applauses were awarded 1 point and audible unappreciative noises caused a point to be docked. Clearly Labour and the Green party come out ahead here, this is partly due to, I think, the straight forward, coherent, and at times aggressive nature of their arguments but also because they tended to dominate the debate; greater time speaking obviously means a higher chance of receiving an applause! Amber rud, by contrast, was not well appreciated by the audience and only received one muted applause during the entire two hour debate, significantly less than even UKIP which managed 6 applauses (of which 5 were muted). Notably UKIP and the Conservatives were the only parties to be mocked during the debate.
My personal thoughts
Jeremy Corbyn (Labour):
There was a certain popular appeal to Corbyn's arguments. His points were simple, straightforward and came across as hard hitting when it came to the economy, healthcare and housing. Corbyn was clearly very well briefed during the debate managing to deflect the 'gotcha' moment concerning voting against anti terrorism legalisation very effectively. While Corbyn's performance has been mixed in the past, he clearly learned from mistakes made on Women's Hour. Corbyn was also on the offensive for much of the debate, targeting the conservative record on the deficit, inequality and corporation tax which came off quite effectively. There was a definite ambiguity on brexit and immigration but Corbyn was very effective in drawing attention away from these weaknesses. Corbyn also knew when to choose not to engage, Nuttal's point regarding Hamas could have been very effective but instead he simply let the moderator drown it out. Overall a very solid performance, Corbyn came across as well briefed but not over rehearsed. Regardless of what you think of him he has the potential to be a strong debater if he is well prepared.
My rating: 8/10
Caroline Lucas (Green):
In many ways very similar to Corbyn. Caroline was effective in presenting the left wing argument and the audience response reflected that. Comments regarding food banks and poverty effected were appealing and emotive while attacks on the conservatives were quite convincing. Lucas was less inclined to attack Rudd directly than Corbyn was, I think this resulted in a few missed opportunities but equally allowed her to present a calmed and more measured demeanour. However she was assertive enough to dominate much of the debate which, I think, will reflect well on her.
My rating: 8/10
Angus Robertson (SNP):
What Angus said, when he said it, was quite effective. But honestly, I actually forgot he was even there for much of the first half of the debate! Angus came across as quite neutral in style (neither aggressive or defensive) and obedient; mostly only speaking when he was spoken too. That's not to say he came across as shy or reserved, but unobjectionable and occasionally even forgettable. Frankly I think he could really have elevated his performance if he only spoke more. Regardless, like Lucas, he did spent a significant amount of time attacking conservative policies and easily deflected attacks from Rudd.
My rating: 7/10
Tim Farron (Liberal democrat):
Tim Farron clearly wants to add his own personal touch to his arguments which is fine, but he would do well to go easy on the anecdotes which are overly long, are only about 75% relevant and occasionally come across as self aggrandizing. And these anecdotes somehow come across as less sincere as Jeremy Corbyn's more populist tone which should not be the case. Another problem I have is that Farron often seemed to be the echo in the room; Lucas made the point (to applause) that May had failed to turn up quite eloquently. When Farron repeated it a few seconds later it just fell flat. Farron also lacked a clear direction like Lucas and Corbyn had with a quantity of arguments (such as somewhat out of place single market advocacy) sometimes prioritized over quality. Farron made some strong points against Rudd and the conservatives but I feel these may even be falsely attributed to Labour or the Greens who made a more consistent case. Not a disaster though, Farron didn't make any major mistakes either; the performance was wooden but it was polished wood.
My rating: 4/10
Like the SNP, Leanne was quite forgettable at times and did not appear to have much speaking time. When she did speak her argument just seemed like the weaker sister of Corbyn's and Green's relentless case against the Conservatives. One problem regional parties tend to have is that they need to fully acknowledge that they are only campaigning from within their region without appearing apathetic towards the rest of the UK. I think Angus got the balance right, but I think Leanne beat the welsh drum a little too much. Her attack on Welsh Labour was one of the few instances where Corbyn was on the defensive, yet Corbyn was able to bat it away as a triviality. There was also a somewhat bizzare moment when Leanne seemed to suggest that Wales was against immigration which she then immediately contradicted by attacking Nuttal on immigration.
My rating: 4/10
Paul Nuttal (UKIP):
Paul's arguments often come across as quite rehearsed, he has a lot of catch phrases he likes to use (how many times have we heard about the city the size of hull). Although during this debate he seemed to have cleared his act up somewhat and presented a more targeted opposition to the mostly left leaning panel members. There were a few moments when he presented quite confident albeit very polarizing counters on terrorism, immigration and foreign aid but equally he took along time to get going having to prefix his rebuttals with 'Let me tell you what it is' e.c.t which causes a loss in momentum. Overall though Nuttal did better than I expected striking a mostly confident albeit hesitant tone.
My rating: 5/10
Amber Rudd (Conservative):
There is no way to sugar coat this, it didn't go very well for the conservatives tonight. Rudd is a very aggressive debater and that tends to come at a price. If there is significant substance behind the aggression then I think the viewer enjoys the tenacity of breaking down an opponent like a brick wall but if the argument lacks substance it can come across as being 'shouty'. Unfortunately I think many people will see the later rather than the former today. Not all of this was Rudd's fault, firstly she was in a very hostile environment deflecting blows from five sides (with even UKIP occasionally kicking while she was down) and having to implicitly defend the seemingly indefensible, why was she even there in the first place! The 'money tree' sound byte came across as quite clichéd when some hard numbers might have been more appropriate (in fact I think Corbyn's argument was more quantitative than Rudd's which doesn't do her any favours). At times Rudd became quite intellectual which didn't seem to work that well with her very aggressive style. To be honest, I didn't feel like I got much in the way of clear arguments so much as simply an attack on Corbyn and Labour. Rudd, when placed on the defensive, at times struggled; notably the audience found her proclamation of an effective conservative record to be self evident quite amusing. However, again, this must be tempered with the inherently hostile atmosphere of the debate; I feel it would have been hard for even the most proficient debater to have done well in her shoes.
My rating: 3/10
Overall I mostly agree with the Audience applause index rankings, although I would rate the liberal democrats and Plaid Cymru as far more forgettable and UKIP as more mediocre than dysfunctional. However to the undecided voter I am sure that Corbyn and Lucas will be seen as the winners and Rudd as the looser.