I've had this lens nearly a month now and like it a lot. It is extremely sharp - which it has to be as I bought for my soon-to-be-arriving A7Rii - and bright, typical of what I expect from a "G" lens. It has completely manageable distortion and vignetting (which isn't much to begin with). Too many people worry about distortion/vignetting when they are the easiest things to correct.
At 90mm it has a nice comfortable reach. Although not as much as some longer macro lenses it is quite satisfactory. And the 90mm focal length allows for some excellent portraiture shots - something I'm not into but many are. Minimum focus distance is 11" but at 90mm you don't need more than that (we're talking about a 'macro' lens here, not a 'micro' - there's a big difference.)
The AF/MF ring is a nice touch and something I'm sure many photographers will like. You can switch very quickly without removing your eye from the viewfinder. But note that the AF is so good and so quiet that you will rarely need to take advantage of it. I only found my self switching one time - and that was to make sure I could if I needed to.
I don't really have any complaints with this lens (although others will - see the next paragraph). To me it's a winner and worth the money. I als bought the Zeiss 85mm 1.8 last week and will run tests with it shortly to compare these two lens. But to me they are different animals. The Sony 90 is a superb lens and brutally sharp while the Zeiss 85, also wicked sharp, is a bit faster, happier in the corners and edges, has that neat DOF display (which works great) and has that wonderful Zeiss 'pop'. I like both equally and will use the hell out of them but for different purposes.
As for complaints I think others will have there is only one - weight. Most photographers who buy this lens will complain of the weight. All I can say to that is if you want GREAT glass, FAST auto-focus, SUPER stabilization, and reasonable reach you should not complain. The laws of physics and great quality require certain compromises to be made and you can't have all these qualities with thin, lightweight glass because the technology doesn't exist yet. Someday maybe, right now not so much.
Sample images from this lens can be found on my Flicker site. Note: these are full-size images exported from Lightroom and can be very large. If you open an image and then click to magnify it may take up to 30 seconds to load, depending on your internet connection.
If you want small, light and cheap then buy the E-mount 30mm macro from Sony - it's a decent lens. Just don't expect this.