Scott,

I would absolutely go with the 880.

Although it has fewer channels (8 instead of 10), it is stereo, as opposed to 2000 which is mono. It also has two effect busses, over 1 on 2000 - those are the two extra knobs (channel pan and FX2).

I think that we have discussed extensively enough the value of having stereo amplification capability when playing arranger keyboards. To me this is a definite plus.

As far as power goes, I understand that it is always a good idea to have your power amp capable of supplying more power than the speakers can handle (otherwise you overdrive the amp's power output, and the harmonics can damage your speaker), although you have to be careful not to turn the master volume output too high. So if in addition to being stereo and having more flexible effect section I get more power for only $70 more, I will gladly take it.

On the other hand, what I would have really liked is having a third built-in amp, which I could use for monitoring myself. Unfortunately, only a much more expensive Mackie 808S has that feature.

Regards,
Alex