Ive read every review from here to Antarctica on these cameras
From all those articles Ive gathered this much so far.
Some Cons
Kit lens leaves something to be desired.
Noise is a little more an issue versus some of the big guns from the other companies but still better than my A55 by far at higher ISOs
Louder than normal shutter sound (I could care less about this)
Slower AF
Hardly any lenses available for them, you can get an adapter and use other lenses and still have AF but you will lose a stop of light and also IBIS
Pros
IQ is really good and is on par to FF from other brands
Usable higher ISO versus my A55
Smaller size so I wont have to lug around a huge body
With all that being said I am still in consideration of getting this in February possibly, I know I want to go FF but still am up in the air on what to do. I can also try and grab a body only A99 for around the same price as the A7 with a lens and still use some of my lenses now, although most are for crop sensors so would have to upgrade those over time also. But I would keep IBIS and not lose any light with an adapter. Also in play is the rumor of another Sony announcement around Jan-Feb and rumored to be some new full body FF and crop cameras, so might wait to she what those are also.
I had a friend who just picked up the A7 and returned it after using it for the weekend. He wasn't impressed with it and said for the cost he would rather get something else, which he did and ended up with a Canon 6D . But I do take his review with a grain of salt because he is know to flip flop cameras really fast and will jump from camera to camera and is never really happy with any of them