Quoted:
My piston MRP is one of my most prized firearms possessions. I would not like being without it. Can't say anything about the Colt. Just know that the mad rush for guns has begun (election season) and will get worse before it gets better. I'm just saying, if you want to secure some new hardware anytime soon, keep that in mind.
I am currently leaning to go with the MRP. I have 5 other ARs, an 18" varmit/tactical rifle that shoots less than 1/2MOA, two SBRs (11.5", 10.3"), a 16" gas gun and a 16" piston, so I'm in no hurry to get this one into my safe. If the Colt 6940p arrives before the MRP does, I will take a look at it. I guess my only concern is that recently Colt's quality control on fit and finish hasn't been the best, but again that doesn't affect function.
I also see that there is a 6.8 barrel available for the MRP. I believe that it is compatible with 300BLK, so that may be an interesting option (two diff calibers).