well.. I went with the big ones.. silver. minor blending required - which was fairly easy compared to switching out triggers or fitting a disco.
once done the mag wells take a beating inside.. It make look perfect for a minute, but after that not so much.
what I like a lot about the big ones is my hands and pinky finger make contact while I shoot.. more contact area means a bit more control .. the smaller ones help feed the mags ok, but not nearly as useful imo.