I'm on a 15cm integrated with a trench board. I'd been advised to get a 20cm one to make the learning easier but for the price I wasn't going to drop that sort of money on an integrated mast twice, so figured I'd just take the learning pain at the start. It really doesn't take that long to get used to and I think it's actually a benefit when trying to go direct upwind as the board isn't as exposed to the wind.
