I have a beat up MC2300. It didn't work at all when I got it but I paid $600 for it. My good friend was able to fix one side of it (borrowing some parts from the other side) and now it is a great "mono" amp. We removed one autoformer from the side that doesn't work to reduce some weight. It is still really heavy but it sounds great. I added a 1/4" input and permanant banana jack speaker connections.
It's a great amp and sounds the best of all the McInosh amps I've had. It seems like all the other smaller amps give me slightly more mids. The 2300 seems a little more flat but still that warm, growling Mac tone.
Jim