Hey kfowler8, my view is it's better the one you know (a bit like a used car I spose). I agree with Max though, get another as a spare. I went down this path (to some degree) when I contemplated not having my MP-2 anymore, what would I have instead ??, nothing out there goes near it for what I want. So now I have 4 MP-2s just in case (albeit my original MP-2 (bought new BTW) is still going strong.
It seems MP-1s are getting to an age that a good "greece and oil change" is required (depending on ware and tare etc) so sending it to Kim (if he's up for it and seems he is ??) for a solid makeover is a good idea (so you have a unit you can be confidant about (crap I never though I'd ever say that about a MP-1
they are just sooo reliable...)). My guess is maybe some of the IC chips may have been dislodged (a little) OR maybe the ribbon cable from the front switch board to the main board has come loose in the crash to the floor ?? That it's in the rack or not shouldn't make any difference.