Hi Martin.
If I ever, ever print anything over 16x20, I'll be very surprised. If I print anything over 8x10 more than a few times a year, I'll be very surprised.
Still, though, just browsing through galleries, lens reviews, etc., it still appears that full frame image quality is better even at smaller sizes. As a relative newbie, I'm having trouble defining just how it's different. DOF differences, definitely - the difference is certainly more apparent in portraits than in landscapes. But perhaps it also has to do with a wider dynamic range? And perhaps even more to do with the fact that FF systems are more likely found in well trained and dedicated hands?
Or maybe I'm off here, seeing something that isn't there. Thoughts?