Hey judasmac, it really sounds to me like this could be a placement issue in a big way. If you're looking for more midrange and up then by all accounts the M2's will likely give that to you ( although the M3 aren't supposed to be slouchers in this area either ). Base is a bit more of a problem. The M3 are supposed to have more base than the M2's and you may be going in the wrong direction with the M2's if this is your primary concern.
I realize this may not be in the cards but my recommendation would be to add a sub. I just got my Axiom sub this week and I'm using it now with some old mission bookshelf speakers ( these are likely hopelesss compared to the M2 or M3 ) and I have to say the difference is very drastic. The whole sound is very much more authorative and full. And the bookshelves not having to produce the LFE sound more open and clearer, its quite a pronounced change.
Now I can't say you'll have as drastic an improvement but I do believe a sub would give you what you're looking for.
My recommendation would be stick with the M3 or try another entirely different speaker if a sub isn't a possibility. If a sub is within reach then return the M3 and get the M2's. Then when funds permit get a sub like the EP125 from the factory outlet or keep an eye out on Ebay or Audiogon.
The very best of luck, Jag
