The lack of brakes is not a problem really, it's quite easy to control your speed by just pulling back on the pedals (you're really attached to the bike that's for sure!)

Fixed gear is the biggest issue for me.

I would love to get my accreditation and ride over winter but they run mixed sessions and there's just now way I can keep up with the superfit, competitive guys who do these sessions even though I can ride the boards safely and competently. If you can't keep up with the group, they fail you.

It's great fun and I'd definitely recommend giving it a go if you can.