Way better than my older 661 assault suit. It's pretty low profile, but still has some bulk to it. Def breathable and cool feeling on runs. The only weird issue was a crash I had where I guess I fell on my elbow, and ended up with a gash and bruising. The bruising is fine, but I don't know how the gash happened unless there was massive rub from something inside the elbow guard. Other than that it's good armour for the buck!