Originally Posted by jb01
I would definitely recommend trying them out with a higher powered amp. first. The M80s can take a lot of juice and like to be kicked hard.
I find some the comments in this thread interesting as I actually upgraded to the M80s back in February having purchased them from another forum member. I upgraded from CSW MC300s, which had 1" tweeters, to the M80s, which have the 3/4th" tweeter, and the first thing I noticed was how much more pronounced the high sounds were such as cymbals. I currently have two of them paired to a Marantz amp running in pure-direct and the only term I'd use for them is neutral. They are each on B&W speaker stands filled with sand and about 2' from the wall and probably 10-12' apart angled at the listening position. They definitely aren't boomy, and I am continually pleased with how accurate they do sound. They can really hit the low notes when called upon as well. Like I said, try them out with some new electronics and try moving them around a bit as others have suggested. If you have the M80s setup properly I don't think you'll be missing out on much, and will save yourself the $$ in the process.
You wouldn't happen to be JeremyB on other sites, would you? I think I've seen someone of your really old posts. If you are, are you still using the P200/P500 combo? How's that working? I use a P205 but have been thinking about adding a P500 as they're being clearanced for $400 right now.
About the original poster's question and the M80s in general, I really like mine. I do know what you're talking about when you say they can sound congested but I've found that placement is a huge factor with these speakers, more so than any others I've owned (dual rear ports are what causes this I'm sure). The highs as another poster said have a really limited stage, they need to be very close to your ears. I never listen to mine seriously unless I'm sitting down where I should be. The M60 as mentioned has a much broader high range and isn't as dependent on vertical placement (I have the MC400 which uses the same tweeter on top of a high entertainment center and it sounds more or less the same when I'm standing up as when I'm sitting down). However, I do think the M80 has more detail when the tweeter is at ear height.
I use the Onkyo 502 with my M80s, the model from the year before yours. It does seem to to alright but there are times I think it's struggling a little bit. I'm not in a rush to go out and get a new receiver because of this because I do think 90% of the time it's adequate, but my next one will be higher powered (or at least have preouts so I can use a power amp). Again though, I think placement is the biggest factor with these speakers.
As far as how the M80s hold up against other speakers at it's price point, I think they do well. I've heard them up against Paradigm Monitor line (listened to Atoms, Minis, and Monitors) within a day of each other and I think they are pretty comparable, give or take a little. I ended up going with the M80s because I got them used for a very good price, but if I was paying full it would have been a tough decision (I was originally comparing M50s with Atoms as that was stretching my budget already, and would take the Atoms out of these two, but I'm not a fan of M50s at all).
Good luck though, I do think these can be really nice speakers when placed right.
Edit: one more thing, have you replaced the jumpers with speaker wire or just done biwiring? Replacing the jumpers made a lot of the congestion you were talking about go away for me. I'm pretty sure they're cheap....using speaker wire should be better.