I've had this camera for over a year, and and it's been nothing but trouble. My keeper rate for shots taken through the viewfinder is abysmally low, despite having spent countless days micro-adjusting my lenses. It's to the point that I shoot mostly using live view, which chews up battery and makes me look like a total dork/noob who is using a DSLR as though it were a $200 P&S! I'm glad I've kept my old trusty T1i. I bring both bodies with me always to cut down on lens swapping, and always put the less used lens on the 70D.
If this wasn't bad enough, the 70D's mode dial cap recently got unglued and is now lost. I called Canon to get a replacement, and was told they don't stock this 10 cent item. Instead, I have to purchase the entire top cover, which includes not only the mode dial, but the hot shoe and LCD as well, sells for something like $200, and requires professional installation. Ridiculous!
I ordered a mode dial cap for the 6D ($25) in hope that I will fit my 70D. By the looks of it, it just may. The number of "turns" is the same, and only a couple of the auto modes are different. As soon as I get the dial cap issue fixed, I'm selling this POS! I'm torn between the 6D and the 7D Mark II for my next body. My primary lenses (all Canon) are the 30mm f/1.4 L, 100mm f/2.8 L macro and the 10-22 mm UWA (which I will keep glued to the T1i). I just sold my 70-200 f/4 IS and have the new 100-400mm F4.5-5.6L IS II USM on order. I'd love to get into a full frame body, but 6D's burst rate (only 4ps) and less sophisticated focusing algorithm (compared with the 7D MII) is a bit of a downer. Then again, I don't shoot sports or BIF very often, so perhaps I can toss these concerns aside in favor the larger sensor? Any advice?