In my opinion, the benefits of this camera:
+ Great picture quality
+ Very good noise performance (if it then rushes times, it looks like an analog recording)
+ Compact dimensions and low weight
+ Pretty much every lens to be adapted (Canon, Nikon, Leica, etc etc ...)
What speaks against it?
- Many sports or wildlife photographer might be unhappy with the speed of the autofocus
Tests for image quality of the camera you can find this by now everywhere. I can say I'm thrilled!
The colors look very natural, the light sensitivity is very very good and when using ordinary lenses obtained very quickly incredibly good results!
I bought this camera to spare me the "stress" with analog photography and just this purpose has the A7 met more than satisfactorily.
I use in practice actually only old lenses I Adapt (usually M42 and Canon FD). These lenses offer some very good image quality at good prices and a not too bad, just go take time.
This is exactly what the camera is also perfect. They can take on just about every trip and every trip and somewhere else because it weighs next to nothing when compared to similarly good imaging cameras and is also significantly smaller.
I'll probably never change back to DSLR as the A7 fulfilled my wishes perfectly :)
While still a Note: I have before my purchase to delve me for a long time with analog photography and learned a lot. Just take advantage of full-frame and the way how to make photos with an analog camera, have changed a lot myself. If you like to take the time to make a good photo and this then also later hang on the wall / stick to the portfolio or the like wants, instead of letting it rot only on an external hard drive, this camera is the perfect tool. I photograph very much as with an analogue, with a little more time and a lot of attention to detail.
If you want it but slightly faster, also one of the Zeiss you can grow FE lenses. Just the 55mm has very good quality and is probably one of the best lenses ever. Unfortunately, the price is again extremely high. You have to decide yourself.
However, very good full-frame lenses, for example, Canon (Canon L) at least as expensive and not necessarily better.