Unless you change the turbo on the GTiR most will run 320 on there standard T28 which is why they run out of puff top end.
They are lighter yes, but they do run the jap style higher compression so suffer for torque.
Mate of mine has a TD06 20G GTiR, equivelent to a T38 roughly, was running 353bhp and 290 odd in torque and it was a pleasure to drive, apart from the lack of LSD and the tendency to light up the front wheels which is very common for higher powered pulsars.
But, he now has a live mapped stage 3 325bhp 2wd cossie, power engineering dyno, and we decided to see which was faster.
Launching obviously the Pulsar has the advantage, but in gear the cossie just pulls away cleanly, thats in every gear, at every speed other than a launch.
Reliability the Pulsar wasnt too bad, pretty much even with his cossie problems wise.
Hope this helps.

Cheers, Mike