I thought I'd share a recent purchasing experience with you - I just bough an EOS 3, however, before doing so I did a bit of research on the 'net, and noted some people had experienced problems with a mis-calibrated exposure meter. So, when I went to buy the camera, I took along my trusty T90 and asked the shop assistant to let me compare meter readings. Testing both in spot meter mode indicated a full stop difference (underexposure) on the brand new EOS.
Naturally, both I and the assistant first suspected the old T90, so we compared the EOS to a Nikon F100 - same result. So then we tried another EOS 3. Same problem (not quite so bad though). A 3rd EOS 3 tested satisfactorily.
The lesson here is if buying a brand new camera, check the metering in the shop - its a lot easier than wasting a couple of rolls and taking it back. While the problem with the EOS 3 has (fortunately) been documented, I see no reason why similar problems wouldn't occur occasionally in other brands and models. And personally, I wouldn't want to do business with any camera shop that would not be happy for me to carry out such tests.