I dont think any t3/t4 will spool as quickly as a 16g, at least not with a "normal" exhaust side setup. The smallest t4 wheel people typically use is the 50 trim, and its almost invariably mated to a stage 3 wheel and .63 AR housing. That gets you to 20-25 psi before 4000 rpm, which isnt laggy if you ask me, but its still at least 500 rpm "slower" than the 16g spoolup. In my opinion, the gains you get from a 50 trim sized turbo well outweigh the extra lag. I launch at 5500 rpm, and never go below that for the whole race. So I dont even see my 4400 rpm spoolup as a problem
But thats just me. Like I always say, if you are having turbo lag prblems, downshift.