Originally posted by tomO2013 I feel that there are potentially more people NOT speaking up about the issues mentioned here (loose grip, erratic autofocus, stuck mirror).
Novel conclusion, given the nature of online forums
Of the issues in your short list (you forgot the reason for your original return, dust in viewfinder), loose grip is the only complaint that seems to be a recurring, at least on this site. Interestingly, several of those reports have come from Canada. Stuck mirror is a serious issue and an obvious manufacturing defect, assuming of course that the mirror came that way from the factory.
To the best of my knowledge, yours is the sole complaint posted here of that nature. Edit: It was brought to my attention that there have been two other reports of that problem on this site. Erratic AF? That is a tough one, partially because the potential for user misstep is fairly high* and partially because it is difficult to differentiate between lens and camera issues. My experience on this site has been that about 2/3rds of AF complaints are traceable to misconfiguration (including AF turned off), botched fine tuning attempts, and/or unrealistic expectations (camera does not read mind very well and stuff like that). As a result, even a legitimate trend of AF issues is difficult to detect and characterize.
Steve
* A month or so, I was a little disappointed to find that shots spanning a couple of days had mostly missed focus, despite my practice to use center point fixed. Going back to the camera, I found that in my fiddling, I had left AF on SEL and the point was other than center. Dumb me, I did not notice that the red AF point had been changed courtesy of the heel of my thumb.