Wilson Combat Mag - cause weak spring along with floppy follower = feeding problems
extended slide release - cause most thumbs are too short to work it
full length guide rod - take the slop out
beavertail safety - for comfort
with ya on the mags, this thing has to have the slide release replaced because it wont hold open w standard mags but will with wilsons due to design.
not sure on the extended slide release or safety like the gi set ups, but still trying to decide
not a fan of the full length guide rod have a competition gun w it