I was wondering how hard it is to ride a 36’’, I’m almost a level three and I wanted something that would be better for covering more distance on and commuting, I can do a 120 degree turn, and hop about 8 inches, does it sound like I’m ready?
Also, how does a 28" compare to a 29" is there a big difference in speed and difficulty?
28" vs 29" is no difference. It’s basically just a bigger tire. This is one case where an inch doesn’t matter. 
Hmmmmmm…
I’m not sure…
When I got my 28er, one of the first things I did was set about trying to see if I could get a 29 tire on her–I found a WTB motoraptor, sliced off a few of the exterior nobs (yes, I have a Sun, but now it is a way cool Hot Rod Sun) and once I had that happening, I must say that the 29 tire felt a lot better. Just a tad bit more in beefyness that pushed my unicycle over the edge into cruising absurdity–for me, that extra inch was worth it.
Any 28 unicycle can be converted into a 29er, even the Sun (if you are willing ti slice off some nobs from a WTB–which by the way, is a lot of fun in a strange sort of way…) --I think it is worth it. Of course, some day, I will have that coker, so who knows…
…and having just compared the two, quite honestly, I discovered that the 29er is not just faster, but easier. The extra mass (in my opinion and experience) makes the wheel easier to control. I have much more fun–hard to believe what a single inch can do, but I guess we can chalk it up to the wonders of physics and mathematics…
go for it
I am level 2 rider and ride a Coker.
So my guess is you are over qualified to ride one. 
The only concern maybe your height; but then again I seen someone’s 9 year old ride one.
It’s fun like heck and I can’t imagine riding anything else(for now).
You’re better than I was when I first got mine. go for it.
it’s a whole new great experience
A 28 is like a big 24, not like a small Coker.
A 29 is like a big 26, not like a small Coker.
Cokers are easy to ride. They just cruise along - and you get complacent, then things happen very suddenly… Anyone who can ride a unicycle at all can ride a Coker. At least one person learned on a Coker.
Of the three sizes, which is best?
That depends on your temperament, your riding opportunities and a number of other variables.
A 28 is a rapier, a 28 a sabre, and a Coker is a bloody great broadsword. Does that help?
if you can ride a unicycle, then a coker is no problem. well, that’s kind of a lie…for most average unicyclists, it’ll take practice to get used to a Coker. it takes forever to learn to freemount them consistently. and for me, it took about ten minutes before I could even get further than half a pedal revolution before falling off. but yes, you can learn it quite easily, 'snot that hard.
it’s easy to ‘ride it’
it takes a lot of determination and saddle time to master it.
it takes a while to regain the low speed skills you have become accustomed to (like idling, and very low speed pedestrian/car negotiation, and learning the enw ways to successfully do what you already were doing.
I learned a lot of finesse when taking the Coker to the trails, and gained a lot of skill that I have been able to transfer over to my MUni, you learn how to not jsut plow throw something (if you have the stock, weaker rim) this video clip shows the coker rim warping and then springin back into shape…it could have easily not sprung back into shape had i landed with my weight on it
get a coker