I have the Magpul stock and fore-end on my 870. I have not found the fore-end to be slick at all and I live where summer temps climb well into the triple digits. I really like the stops on the front and rear of the fore-end. I had a surefire fore-end and while very well built it constantly interfered with my sling.
"You live more in 5 minutes on a motorcycle
than some people do in a lifetime"-B. Munro