I know that I'm a bit late but I've only just seen your post.
I have the earlier version of the Mixdown and it isn't a bad desk considering the price. It has a few little foibles compared to more modern desks but none of these are show stoppers. The EQ is interesting - only 3 bands with a fixed HF frequency and sweepable mid and low frequencies. I've mainly used it with analogue recorders and noise was never a problem.
With any mixer of this age you need to check all the pots and switches - I found that the dual gang pots used in the EQ section had a shorter lifespan than the single pots used elsewhere.
The XLR outs are also wired a little strangely although I always used the jack outputs. None of the outputs are balanced and neither are the tape inputs. The line inputs are balanced though.
Let me know if you have any other queries - there is a service manual floating around the net.