It has been just shy of 2 months since I purchased my a7, and I still could not be happier. I have used at every event/wedding I've done since, but with the mentality of "what can this camera NOT do" rather than using it another piece of gear or with thoughts to replace my Canon 5d Mark III. Every time I use it, it still amazes... the size of this camera with a Full-Frame 24MP sensor, never thought it would happen. For those of you old enough to remember film, it feels like an old Pentax K1000 in your hands, but smaller. And like the Pentax, you look through the viewfinder to focus and set your image. But, with the a7, the viewfinder is an "EVF" - Electronic View Finder. You basically see what the camera sees and how the image will look once the shutter is pressed. So, it is a digital image that visually adjusts when making changes while framing your image (+/- exposure). It does help but it takes a while to get used to and not just using the meter and "assuming" what is going to happen.
Where this camera really shines is low-light. The bottom 5 images were shot from 1250-3200 ISO and you can barely tell when compared to under 800. There is a little "noise", but it feels more like old film grain then digital noise. The 2 "money-dance" shots were done with a videographers LED light only, basically pitch black except for his very small light. It looks more "earthy" and real than my Canon on those shots, definitely pulls more out in the highlights and shadows.
Now, will it replace the 10-pound Gorilla Canon... not yet. Could I do an entire wedding with 2 of these... most likely yes, but the lens choices they have right now are limited and I use so much off-camera flash that I would completely have to change my style. Also, it does not have the FPS (frames per second) the Canon does, not does it have as many focus points. If they decide to get into TTL flash, add a few more prime lenses and do a few firmware update, may have to think about it. When you can reduce gear and get AMAZING images, it makes you think.
This is a camera I will have for many many years. I will continue to use for personal family trips, carry as a 2nd camera for events and basically keep it with me wherever I go. Currently, it's going to set you back about $2400, but I assume by Christmas it will be under $2000 if not less. Sony updates it tech fairly quickly and they have been on a tear lately. There is now an a7r (36MP) and a7s (4K video) and rumors of a Medium Format camera as well... will be fun!
Thanks for reading and hope you all enjoy the pics.