Rem.700 J lock system

[Dskiper]

hello, can anyone tell me the disadvantages of "J"lock that was used on their actions?Is it worthwhile to change to a after market replacement such as can be sought from midway or brownell?Is aluminum bolt shroud & pin assem. ok or go with rem.factory parts?Both my rem.VS.223+.22-250 shoot 1.25" 200yrd.groups with Blacck Hills ammo.Am I wasting money changing? thanks, Dskiper