In my mind, the 14.5" upper is more of a close-in hammer oriented towards 110/125/130gr ammo using a red dot or 1-4/6/8 LPVO.
I wouldn't swap uppers and throw that same 3-18/T1 on it, as I don't think you're getting the same performance capability at distance.
For reference, and I haven't chrono'd the 14.5" yet so these numbers aren't solid, here is a *potential* comparison. ECC velocity is solid, chrono'd many times.
16" ECC - M118LR Suppressed - 2550 fps - 29.92/59/40%
14.5" CC - M118LR Suppressed - 2440 fps - 29.92/59/40%
16" would go transonic at 770 yards (7.5mils), subsonic at 980 yards (11.7 mils)
14.5" would to transonic at 710 yards (7.2mils), subsonic at 920 yards (11.6 mils)
So you're knocking about 60 yards of supersonic distance off from a 16" gun
I didn't due TOF, energy on tgt, or wind drift comparisons, but the 14.5" is going to be worse in every category.
For me, cutting down a little bit of length isn't worth losing the velocity. I won't be running a 14.5" gun at the class this year, I'm sticking with a 16". 14.5" gun has a dot on it.
Just my $.02.
***ALSO*** before anyone gets their panties in a bunch about why I knocked off 110fps for the 14.5" gun even though it's only 1.5" shorter, this is what I'm basing my guess on:
Of the FOUR EMC/ECC 16" guns that have come through my possession, they have all chrono'd between 2525-2550 fps using M118LR. Dunno what it is about those barrels, but they were always a touch faster than other 16" gassers from other manufacturers. I expect to see around 2500 for a 16".
I've chrono'd THREE of the newer E2 16" guns, and they are down in the 2465-2485fps range with the same lot of ammo. So a touch slower than what I'd consider average. So I'm guessing that the E2 CC is going to be even slower still due to the decrease in barrel length.
I'm also thinking that 14.5" might not give that ammo enough length for full powder burn, but I have nothing to base that on other than a hunch. Maybe someone can run Quickload to see if that is correct or not.