This is your subjective opinion.
This is the part where you are objectively incorrect.
Both share the same gun.
Both share the same hull mg.
They differ on the coaxial. (TA has double DPS but doesn't get access to MG gunner)
TA has +240HP, +7popcap, +15sight.
It has a slight higher vet xp value. The offensive differences against a normal Tiger are applied through it's veterancy (http://stat.coh2.hu/vetraw.php?filename=tiger_ace_squad_mp)
And reload speed ? (only for curiosity, i am not entering in the debate )