Really hard to say about the difference with the tubos as it was a couple of years ago when they went on. Stuffed if I can remember. When they went on the car went from 190RWKW to 260 RWKW so it all felt pretty damn good! I don't recall feeling any additional lag when they went on. Never driven anything else so can't comment on the 5s. I would like more top end in mine, but I might already have that, but with so much mid-range torque it might be masking what is actually a good top end perfomance. Just want that last mad rush for the limiter. Might also be the tune. Tuner has said it's tuned for torque as it makes the car quicker (in real world situations) in almost all but flat stick applications (which never happen as often as you think).
I've heard journos challenging each other to keep the trottle pinned for more than 15 seconds in a Veyron as it is apparently almost impossible unless you've got a runway at your disposal. Same, but to less extent, might apply to the old GTR. Wide open for long periods = not very often.
Oh yeah, oil temp about 100-110 on the track.