Not terribly so against infantry of course. Just against emplacements, mediums/heavies etc. Haven't tried to see if it can bring down a building with an MG in it (can it?).
I quite like the Overwatch commander in the support role it occupies - nothing crazy standout but helpful abilities; for example no one bothers to minesweep the flared cp's etc and the Goliath is okay because people just do not expect it (a small consolation).
Anyway - I suggest to increase its damage (not radius as to not disturb its current ok'ness vs infantry). Either a bonus to UKF emplacements in brace etc or a general buff in damage. Reason being you should be rewarded for pulling it off.