Hey I'm wanting to go for these options for an upgrade.

[ak2m4]

Is the MR a batter match with the XT barrels?

I ask because had good results with both on a variety of barrels, and would I'd happily recommend either - I'm just wondering why one would be preferred over the other.

I mention MR since I do all my testing on them and the hop window on the XT inner barrel is enlarged for the larger patch of the MR.  It really doesn't matter too much, both will work.