Don't own a Gen 4 tho I've played with them at my local gun store. I don't like the texture nor do I need the interchangable grips. That said I will never own one so I don't need to worry about how they feel. However, I don't like the feel of any grip rubbing against my side. I wear a tee shirt for that reason.
"AN ARMED SOCIETY IS A POLITE SOCIETY"
NRA Endowment Life Member, Glock Armorer