SAL-2875 -> Tamron 28-75?

Butterfingers here broke the SAL-2875 - this was rapidly becoming my main iens for general purpose shooting in preference to the Zeiss, mainly because it's half the weight - though on the other hand you can definitely see why people buy Zeiss lenses.

Anyhoo, I need to replace it and I'm reading a lot of stuff on the web which is telling me that the Tamron 28-75 is practically the same lens, especially in terms of IQ. True? False? What do I lose by going Tamron (which has, I noticed, a spectacular warranty, though it wouldn't have helped in this particular case).

Tamron_28_75_main_tn_medium vsX158sal2875-f_medium?