I've had a a33 for years and have loved it. I'm looking to upgrade. The main focus of my photos currently is high schools sports. I'm shooting fast moving objects in poor lighting conditions. Many of the gyms I'm shooting in are older and the lighting is bad. I'm just shooting for a hobby that I enjoy. I do a little landscape, and macro.
I've been told the newer Sony cameras are able to shoot at a higher ISO with producing less noise. I'd like to keep with a Sony camera and also if possible the same lens mount without using adapters. I've also been told that the translucent mirror in the a33 "steals" some of the light for viewing, which compounds the problem of shooting in low light.
What would you recommend as a step up camera? I don't feel the need to go full frame. I'd like to keep to less then $2k for a new body.