The bumps in the feedneck will have a miniscule affect on the feed rate of an agitated (Ricochet, Revvy, eVLution, etc) or force-feeding (Halo, Magna, VLocity, etc) hopper. It's a good investment because they aren't made of cheap plastic, but the ridges are a moot point.
www.sundragonpb.com has MR feednecks if I recall correctly. Reputable company and an awesome owner.