I went through a similar problem last spring. I am a long time Minolta user, then Sony a65. I went on a Sony demo at a camera store and could use any equipment for the day at the Woodbine Oregon Tulip Festival. I used the a7Rll with an adapter for my own lenses. I was blown away by the difference. Then the Sony a99ll came out. After much debate, I got the a99ll and love it. There are plenty of great lenses out there for the A-mount system including Zeiss. I do not regret at all getting the a99ll. I also picked up a Used Sony a6000 as my travel camera and I have a bunch of $10 adapters so I can use all my old canon, Zeiss, and other lenses on it. I see that Sony just announced a new camera in the a7 series. The a7Rlll. The specs are about the same as the a99ll as is the price. Note that you can use ANY A-Mount lens on a e-mount camera via adapter. Think hard and long about switching brands. Sony makes most of the sensors for Nikon and many of the cel phones. A vast majority of TV stations use Sony equipment. Many independent movies, TV commercials, and instructional videos are shot on the Sony a7S camera. See if your local camera store is doing a seminar soon and play with the cameras. Here in Oregon, Shutterbug Cameras do seminars every month and offer a free class on your chosen camera. I drove 4 hr to attend their show and tell, and it was well worth the trip.