I find my 24" spot on for me, i rode mod for just under two years to get me into the sport, once i had all the basic moves and was starting to get better in the sport i wanted to move up wheel size, i had a go on a fair few peoples stocks and found they would have been too big for me. So i had a go on one of my friends because simple 24" which felt perfect for me, a fantastic middle ground for stock and mod. I've now brought his because simple and feel i improve on it quite alot. I also find with bigger wheels its a massive amount easier getting from one place to another and so saving energy for when you start to ride trial. The only downside is for me, if you want to run disc brakes they find it harder to grip the disc with a bigger wheel unfortunly(spelling) however i think this might be down to me because 26" riders run 160mm discs and ride fine.