Any recommendations other than the two speakers I mentioned above? These will be just for music listening at fairly close range.
Maybe Paradigm Mini Monitors ? Only concern is that they may be closer in sound to the speakers you already have than to the M3s.
Your challenge is that you've sort of moved past looking for the "best" speaker and are now looking for "the best speaker for you". You're going to have a tough time finding a "better" speaker than the M3 in that price range, but you've listened to enough speakers to start zeroing in on "your" ideal speaker.
My guess is that you'll like the Ascends. The 170 is obviously a closer match to the M3 than the 340 is, but it sounds like the extra size & output might be what you need. The Ascends are also reported to have a bit more of a "mellow" sound compared to the M3s which might help.
Anyways, you're basically at the point where different speakers offer slightly different tradeoffs at the same price point, and one of those sets of tradeoffs will appeal to you the most.
Or you'll end up spending $1000 on pair of speakers. Sometimes that happens too