I have 18's on mine, and will be dropping to 17's when I get new wheels.

* They rub if you give it shit on a roundabout with a passenger in the car. Infact if you're really on it they rub with just me in there, and I'm only 14 stone now!
* Tyres are more expensive.
* It does tramline a bit, not bad but a bit.
* The sidewalls are so low profile there's no squish for a good standing start.

Unless you have to cos you have some mahoosive brakes I'd stick to 17s.

Mine is pretty decked, but I don't like the way they're tucked in the arches on the back: