I switched from years of sportsbikes to a GS, now looking at an S10 (and have ridden a couple)
Modern bikes are far more capable than modern riders, the technology improvements in the last 30-40 years ensure most riders can't get near the limits of "average" motorcycles, forget your S1000RR etc.
I am as fast on a GS / S10 / CB500 in the twisties as I would be on a ZX10R, I had a mate race CB500's in the late 90's, on a track he was faster on his 51BHP, spindly framed, skinny tyred commuter bike as me and my mates were on bikes with twice the power and the most modern suspecnsion and chassis technology.
This is the reason I love bikes like the S10 even more, as I can use more than 10% of the perfromance, and amaze the Power Rangers on their YZGSZX1000RRSP's as I sat up the chuff on the twisties on my big, overweight, underpowered, slow, crappy bike on rubbish skinny tyres.
The best thing is I don't find myself doing 150mph everywhere and having to worry about doing a stretch at her Majesty's pleasure as I have left the fast roads behind, and now have fun on nadgery little lanes, with crap on the road and preferably grass or mud down the centre, this is where 50mph can seem pretty damn quick - and no "fast" bike would even get close.