Your barrel will probably play more into the accuracy of your build more than upper receiver, as long as it's in spec. Aero will work well, but Vltor/Geissele is a step or two above, in both price and build quality.
If you'd like to save a little, BCM uppers are also built a little thicker in areas and have VERY tight receiver to barrel tolerance.
My MUR with Geissele rail and LaRue barrel shoots sub-MOA as long as I do my part and feed it quality food.
I have no evidence it is more capable than any of my other rifles, but I can say it is capable for longer simply due to the barrel's thermal mass. I have not noticed deflection of the handguard either, which is present in some of weight weenie guns.
Last edited by OrbitalE; 02-14-17 at 01:05.