I've owned both, and I would say stock-to-stock, the RB26. I don't have the best data experience, being that my supra was auto and BPU, and my GT-R is slightly modified (Trust FMIC, 4-in Apexi N1 Exhaust, DP, HKS twin intakes). Supra was 400 bhp, skyline is probably 350 bhp. The power/torque curve is more linear and responsive with the skyline, due to the true twin setup of the small Garrett turbines. The Toyota's CT26 turbine's are nice, but the sequential set-up creates a minor lag (especially in an AT), which can be disappointing, 'til the 2nd turbine spools up and then you're off!

The skyline is much more fun to drive and feels less bulky in the zigs, and the supra feels more like a drag car.

What would be interesting, is to, somehow swap a 2jzgte into a GT-R (with AWD), and swap an RB26DETT into a Supra and see how that pans out. Of course, I would have to convert the gte to a true twin set-up for the response, but I bet I would like it more in the GT-R. Just gotta have that response!