I'm a photographer, primarily wildlife and nature. That means I have some fairly specific needs, with gear I tend to use a lot (longer focal length lenses sometimes, tripods, sometimes flashes and flash extenders), and less need for some other gear (reflectors, big soft boxes, laptop for tethered shooting, for instance). I'm fairly used to carrying some heavy gear long distances to make just a few images sometimes. There can be a lot of stuff to cart around, and I'm not getting any younger.
My first DSLR (after a series of bridge cameras) was the Sony a100. I used an old Canon film SLR decades ago and had no modern lenses, so I wasn’t married to any lens system. And I like to support the underdog, and I've never been a traditionalist, so I did the Sony system. I’ve never regretted it. I upgraded from the a100 to the a700 as soon as it was released, and was using that as my primary camera for a while. I got the a580 as a back up; it’s barely been used and almost new. I got the a77 as soon as it was released, too.
I still love the a77; it does everything I want it to do (except maybe high ISO). Before the a77ii was released, there were a lot of rumors about the specs, the most prominent being it would have a 32mp sensor and be mirrorless. I don’t really need 32mp, but it sounded interesting, and I planned to upgrade. But then it turns out that the a77ii would still have a 24mp sensor (yeah, a generation or two improved from the a77), and maybe a better AF system, but the new a6000 already had all that, and at a quarter of the size and weight of the a77 (with the vertical grip, which lives on the a77). I decided to get the a6000 mostly as an experiment until the a77ii came out – I figured I could return it to Amazon after I played with it.
After I played with it, I really enjoyed it. Light, compact, and image quality at least as good as the a77. I just used both cameras with the barking Mamma Marmot, and the files might (might) be slightly better from the a6000, but for all practical purposes, the IQ from the a6000 leaves nothing to be desired.
The a77 still has some advantages: The controls are easier to use (I have big hands, and wear gloves most of the time at altitude and in the winter, and the a77 is easier to operate). Accessing the controls on the a6000 (a smaller body, obviously, with smaller buttons and controls) is more difficult at baseline, and I have to set it and leave it if I have gloves on. I don’t change settings that much, so not a big problem. It’s also more difficult to set a specific focus point. On the a77, I use the toggle on the back and quickly put it where I want it (usually the critter’s eyeball). Focus is ALWAYS spot on with the a77. It’s taken me a little while to fiddle with the a6000’s focus system, and I can do most things I want, but it isn’t as easy or precise as with the a77. The max shutter speed on the a6000 is only 1/4000, compared to 1/8000 on the a77. Usually not a big deal. The other disadvantage of the a6000 is a limited buffer size – shooting 11fps burns it up pretty quickly; I can still shoot brief bursts while it’s clearing the buffer, but I have to pace myself. The a77 can rattle off frames and I usually don’t hit the buffer too often. One thing I do like, that I initially thought was a disadvantage, was no external battery charger; lots of folks complained about that, but I use the same charger for the a6000 that I use for my phone. I charge it while driving to locations, I charge it beside me on the desk, and when traveling I just have one tiny cable. Much more convenient.
The a77 is still a great camera, but the a6000 is light, compact, and a lot of fun. I'm immediately noticing that rather than carrying two or even three camera bags along with my Think Tank camera harness and modular mount system (frequently crammed into a giant plastic storage bin for convenience and to keep everything together in the car and in the basement), I'm down to one small Think Tank bag for both a6000's, one with the SE 70-200mm f/4 G, and the other with the the 70-400 with the adapter. I can keep everything in the front seat of the car and have easy access to it, and only have to make one trip from the car.
The first image is from the a6000 with the Sony FE 70-200mm f/4 G