It is a 16". Hopefully it makes it easier and not harder to learn how to ride a bigger wheel. I'm going to start looking for a 24". This thing is ridiculous looking, and I look even more ridiculous riding it. Time to go try to ride 80'!
I learned on a 20", but have a 12" uni for my daughters (twin 3 year olds - no they don't ride yet). I have tried it a couple of times and it is way too tough for me right now - partly because the seat is waaaay to low and partly because the cranks are so short there is not much room for error. I can ride a 24" though. So all this is to say that I think it is easier to move up from the 16" than it would be to move down from the 16". But you would probably look even more ridiculous on a 12" unicycle. 🙂