It's somewhat weak, and has some narrow uses. It's what I consider a budget unit, lots of caveats, gotchas. When I have those, I have to somewhat interrogate the would-be buyer, to make sure it'll work for them as needed. It's not at all the same as the DataVideo units like TBC-1000, TBC-3000. Sharing the same "TBC-X000" model name was very misleading.
BTW, there's an ancient TBC-2000 at eBay
right now. Avoid that model too!
Most of these units are in awful shape. The TBC-5000 was odd, made to marry the DVKs, for a weird analog+digital studio. The main buyers were colleges and schools, and were abused by hamfisted careless students. Buttons don't work, the units were left on for days at a time, etc. This is why so few survived. Ignore all the "tested" and "working" BS, unless the person operated a studio, not just some recycler or estate seller.