After owning this camera for over a month I think I can finally share my thoughts on it. Since I've owned an A7 already, I can definitely say that his feels/performs like a "mini A7". You're working with the same interface in a smaller body with fewer dials/buttons. It still has an OLED viewfinder, like the A7, and it even includes a convenient little pop-up flash that can be pointed up to bounce off a low ceiling. The fact that it fits in a jacket pocket is a huge plus since you can have a quality camera in many places where you can't have a DSLR, like a concert. Here's a little more info on the third generation Sony RX100.
- Weight/Size: I don't know what to really compare the weight/size with, but it's perfect. There should never be an excuse for you to never have this with you and settle for iPhone photos. It's not much heavier or bigger than my iPhone 6. Its build quality is very solid as well, being made of mostly aluminum. You'll have this compact with you at all times.
OLED Viewfinder: The A7 introduced me to an Electronic Viewfinder for the first time and if you remember that review you'll know that I love it! Personally, it's easier to see than with an optical viewfinder. Plus what you see is what you get, making it really easy to make quick on-the-fly adjustments to fix exposure or focus. This little 1.44m dot display will not disappoint.
Image Quality: This is the BEST compact camera I have ever used in my life. I would easily prefer this over my old Nikon D40. I think a lot of people would. Sony's style of cramming massive sensors into tiny bodies paid off, the 1" sensor wows under all conditions. I've pushed it to ISO 12,000-something and while it wasn't jaw-dropping it was still useable for sure. It'll blow your phone's camera out of the water and keep up with your 5D.
Lens: FF Equivalent 24-70mm f/1.8-2.8. Enough said.
- Battery Life: It's pretty simple I guess, small body = small battery. It lasts about 350-400 shots, so I'm constantly turning the camera on and off as I'm shooting. A spare would easily solve this problem.
Like I said, this is the best compact camera I've ever used. If you're looking for a camera for vacation or as a back-up, get this. You will not regret it. Seriously.