To be honest, upto around 120-ish it'd probably feel surprisingly similar but at the speeds where the 600hp cars start to hit aero resistance the 900hp ones just seem to push that aside and feels like it keeps accelerating past 200mph like a mondeo does to 110mph.
One surprising thing is that, as an ex Skyline owner myself, the RS is so well insulated in comparison that it has almost none of the Theatre, with no real cabin noise of induction kits or dump valves etc which can make it feel a bit soulless at times, regardless of the utterly ludicrous speeds it can reach.
This, raced my mates Mustang a few times, standing race I always win to 100mph or a quarter mile run.
But rolling race as soon as I am into 4th and into triple digits he just drives away from me at an ever increasing rate of knots, he has 200HP plus at the crank on me, of course he has even more at wheels been RWD and a manual.
Would love to see you and him do a rolling race, would certainly be close for sure as you've probably got 100HP on him, but at the wheels probably not miles apart and he is lighter too, be an interesting race. You doing a Vmax200 event in the future at all?