It is rare to see a GPX doing Moto Gymkhana. It makes a nice change from the common "this is the bike I'm selling" vids. It's not the best quality vid but the little mono at the end makes up for that.
I'm keeping BT45's in mind when I eventually replace the tyres on my bike, not that there a lot of choices any more. Metzelers always worked good on the RC17 so it will come down to a choice between Metzeler and the Bridgestone.