I've ridden the Power Expert for a couple of years and I loved it like a fat kid loves chocolate cake. I've done centuries and felt great. However, this year I did a century ride on my Expert and I got saddle soreness that left me off my bike for three days.
I thought that maybe a Power Arc would solve my soreness problem. It feels very different than the Power Expert. I didn't feel pain with the Arc; however, it didn't feel as comfortable as an Expert Power saddle. I sold some of my older saddles and I bought a Power Pro. I'm now selling my Power Arc Pro. I'm still trying to get used to the level 1 padding on the Power Pro. I'm not sure how long I should give my sit bones to get used to my Power Pro.