not really, they’re all mission specific. sure, they’re all m4/m16 based builds, but each are very useful for their intended purpose. you wouldn’t run a mk12 in a cqb situation, nor would it be ideal to use a mk18 in a recon at distance mission.
I did say “except for the obvious caliber change and SBR’s”
the RECCE, SPR, Mk 12, etc, etc, are all almost identical. When I finish my current build (if I finish, the way my wife is going) I am going to give it a cool name than see how many I can sell on “other forums!” Really there doesn’t seem to be a dimes difference between them.
When my pistol build reaches it’s peak configuration, I too am going to coin my own new acronym for it. Maybe SPP, Special Purpose Pistol? After all, it already sports a 1.5X4.5 rifle scope and does 5 shots into a 2.5" group at 100yds.