Dropped by Kixs today (thanks for the tip!) and picked up two N&F shirts. One was the multicoloured check and the other's a chambray with cool white flecks on it. Sized up to S (I have a blue oxford in XS) and it fits a lot more comfortably now. Still slim but not supertight - the XS shirt is a bit like wearing a Wings + Horns henley. The front part hangs about 1" longer than I'd like though. The sides are still too short to tuck in properly so I probably have to get it altered.