I'm with Tom on this one (scary, yeah, I know!
).
My reaction to hearing MB wax eloquent about bolt-action ARs was that line from the original Jurassic Park - "Your scientists were so interested in whether they could, they forgot to ask themselves if they should".
I was of the opinion, based on readings, not experience mind you, that the bolt vs. semi-auto accuracy issue was done in a long time ago. Semi-auto Barretts, Lapuas, even M-14s have all proven to be very effective long-range weapons, especially in the sandbox in hands of very skilled sniper teams.
So what's changed, other than the marketing guys had "a really good idea!"? /sarcasm