i have a Gen 2 SD lower. i really like it. LMT upper fits tight, no slop and USGI mags drop free.
color match with LMT upper is great, almost perfect. only complaint i have so far is that the finish on the lower is a little soft. doesnt really matter to me, though. scratches give character.
not quite as tight as my RRA lowers, but those were almost too tight. DPMS was sloppy with my uppers. (RRA & LMT)