I think you will find (and this is where the Jap bike owners start to cringe) that the Aprilia (now its owned by Piaggio, the 4th largest bike brand in the world) is actually cheaper to service and run these days.
However that depends on where you take it
I have a brand new 06 RSVR, had it upgraded to include all of the bits off the Factory bar the Carbon styling,
servicing costs me £200 for the minor inc VAT and £240 for the major, and i know that Kawasaki and Suzuki are another £100 on top of that when it comes to the major services to start with.
That being said, the GSXR1000, ZX10R, R1, CBR1000RR are all tried and tested and solid perfomers but each bike fortunately has a different character to it.
But a GSXR750 with a TRE fitted and a powercommander added will keep up with any GSXR1000 on all but the last 10-15mph of its top speed
The 750 shouldnt be underestimated, its would take a skilful rider to outride one of them on any bike these days, the GSXR1000 might be the most awesome package by most people's standards but the GSXR750 in terms of handling and power is supposed to be the perfect blend of track and road for the UK especially.
The definitely need test riding thats for sure because a K61000 feels nothing like a K2/K3/K4 thats guaranteed, much the same as the 1998-2003 RSVR feels nothing like the 2004 onwards.
Lastly 1000cc bikes dont have to be putting out 180bhp to pull the arms out of their sockets, they can quite easily do that with 130 at the wheel and knock out over 78ft/lbs of torque quite happily
Get out there and test ride the bikes, i am on my second Aprilia now, the first one was trouble free in 28000 miles, and cost less to service than my ZX9R (which was as quick as any of the new bikes) and their reliability shouldnt be compared to that of the early Italian bikes or indeed the early Ducati's (which is where most people seem to get their comparison from).
Lastly, what is said about the ZX10R is spot on, its a full on animal, far too twitchy in the wrong hands, and seems far too much on/off.
A friend of mine has had 2 RSVR's, before moving over to an R1, then to a GSXR1000, back to an R1, over to a ZX10R before finally moving back to a new RSVR (he is an accomplished rider that happily knocks out a 52 second lap of Brands Indy circuit).
And he was still tempted back to the Darkside
seriously though, with all the new bikes, you need to get out there and test ride them, all have their own talents
good luck with whatever you choose, all of them are a far cry from what you are used to with the ZX6R
