very similar...
both built 87mm bore engines...both with extensive headwork including 1mm oversize valves...both with 280+ deg cams...both with Hypertune plenums (6 throttle on the circuit car and single throttle on the drag car) both with big intercoolers (Apexi drag on the circuit car, Trust drag on the other) both with similar exhausts 3 1/2" circuit 4" drag, both running Power FC (recently upgraded both cars to Vi-PEC ecu's) , Z32 AFM's and Blitz dual soliniod EBC's
We really had to push the circuit car to crack 450KW...the drag car was slightly better everywhere and did it with the GT-RS's without even raising a sweat.
My vote for simplicity would be T04Z as they are easier to get them to perform...but for best results the GT-RS's are the pick if you know how to set them up correctly.
The T04Z is more forgiving if the set-up is lacking in an area...the GT-RS's wont let you get away with it...everything must be spot-on. A 3 litre bottom end may make it a little easier to get right as the extra capacity will help them.