I bought a pair of Ride ISO 2s about 6 months ago, and loved them. Went looking for another pair, saw the Guide ISO 2s, read some reviews and thought I'd take a chance since they're $80 cheaper. I love these just as much, and maybe more due to the money saved. Both Rides and Guides are light and comfortable (pretty much feel the same to me), the only noticeable difference being that the Guides feel a little stiffer in the soles. They're advertised to have more stabilization, and they do. The extra stabilization doesn't affect my run or comfort at all.For reference, I run an average of 15 miles a week (3 5 mile runs). I don't have much of an arch in my foot, and sneakers with heavy duty arches are painful for me. Can't run with Nikes. The only other running sneakers I've ever found comfortable were Aididas and New Balance. I also have a narrow foot, and these work well with that. Not much more I can say - I think they're great!