I've run Mk8 rails on precision builds before. In fact, I have a 15" Mk8 on the shelf waiting for whenever I get around to building another precision upper. I may pair it with a 18" or 20" Criterion Core barrel for a modernized DMR setup.

PROS:
Barrel nut doesn't need timing
No issues with normal lo-pro gas blocks contacting rail
MLOK hardware should have proper clearance
Doesn't have the McDonald's straw feeling that some thinner rails do
Stout

CONS:
Not the thinnest rail
Not the lightest rail
Not the cheapest rail