what about 19''s? or is that tooo Max Power?
I'm tempted to go to 18"s, but I love those alloys on Shiny's GT. Suwheet. He's got suspension mods, which may improve ride over the bog standard set up, or he is used to a hard ride on 19"s.
arguably, 19s are more for bling than performance. but hey, i love them.
they certainly make for a fairly hard ride, but i would not call them harsh except over sharp ridges or potholes, which i try my best to avoid (slow down or swerve if safe). i think the tyres make a difference, and the toyo Proxes4 225/35 are nice and compliant (even running 39~40psi pressure in my tyres); though a smidge too noisy for my liking. this compares with the original 17" bridgestone RE050 tyres which must have stiff sidewalls - they were generally harder, and had LESS ride comfort (36psi). go figure. when i changed the wheels/tyres, i already had the suspension changes, so that was all that changed, meaning the differences i'm talking about were attributable only to the wheels/tyres. though the KONI Sport dampers, in themselves, improved ride quality considerably.
having said that, 19s would not be for everyone, and 18s is probably a better compromise for most people. i DO have to be careful about deep potholes or big ridges and debris on the road - to avoid risking buckling/bending a rim.
19s on GT's seem popular in some countries, including Germany, where i am also a member of some GT forums. they seem to like their bling! less popular in the UK or australia from what i can tell.