i bought 2 extra locaps when i got my gun, and then a high cap, then a couple more locaps. i never did use the high cap except for once, so i traded it to my brother when he got an M4 for his locap.
now i have 7 locaps, so im thinking of loading them to just 34rnds.
they add more realism (which is why you spend $1000 on a gun in the first place) plus, how are you supposed to ware a vest if you only have 1 mag?