Ken or Boris?

Is it just me or have the London Mayor candidates all said the same thing?

I listened to their last gasp sales pitches last night and couldn't see daylight between any of their policy promises.

So, who do you choose?

Is it bad form to cast a vote based on personality alone? (born-again buffoon or old school maverick?) Or should such a choice always be anchored in potential performance? Surely both sets of reasoning are as 'illogical' and risky as eachother? How do we make the right choice?