t2 TBs usually have larger fuel tanks, better defense, higher DP, and carry higher damage torps.

in exchange, they are usually slower (flying speed), with longer loading time, and, take up more plane space. 

again, thats the general trend.  there are some exceptions

Go with T2.

More damage and resistance to AAW due to aircraft stats (more armor and DP).
More damage means they can go through bulge easier so it's pretty important to TBs.

Thay also get more air attack power meaning that they just might shoot down fighters once high level (100+) and BVE.