I've goofed around on a couple Stouts, just in a parking lot but never really riding it on a trail. But just from that I felt much much more comfortable on the 19" frames. I'm 5'10.5", 30" inseam and relatively normal proportions. If you can ride them, I know how difficult that can be if you're not near a Performance or SE dealer, there just aren't enough of either around. But try to get on them if you can. If you're 5'9" at 13 years old I have a feeling you're going to outgrow a 17" pretty quick.