So, here is the report after driving the m80s for about a month every day 8-10 hours
(they're in my home office, about 400 sqft or so with sloped ceiling) to get them settled
in. I won't open the can of worms about whether components 'break-in' or your ears
break in or not but I can say that there is quite a dramatic difference in the sound
to my ears after a month.

first the setup: NAD 541i (and tuner & other sources not as good) pre-amped with a
TacT 2.0 going into odyssey stratos monoblocks into m80s. All wiring groenberg (again,
maybe there is no difference to lamp cord but the cost compared to total makes it
irrelevant, I'm going for puresilver interconnects from source to preamp just to
check I don't miss a cheap improvement). Started driving via digital 44.1 interface
and ended up going 96kHz oversampled analog which sounds significantly better
(I'm sure someone here will claim oversampling is a non-issue either). Digital
sounds more precise & lower noise level but much thinner in the middle and highs
(I assume it's the harmonics missing), maybe due to clock jitter? Shows on female vocals.
Syncing the clocks on TacT and maybe Tascam CD player is one of next projects.
Started sitting fairly close (6 feet or so) and moved back to 12feet. These speakers
need a lot of room to sound great. I prefer listening on-axis, I found with
measurements that off-axis the speakers seems to loose flat response fairly
fast (maybe it's my room response though).

Soundstage: Width is very, very good, going on good recording beyond speaker outer
edges easily. Most amazing stuff was actually the clock on the 'kid from cleveland
in the comfort of routine' waters' 'Amused to Death' (recorded Q-sound) that
clocks on the left of me, basically to the left of my head, about 8-9 feet in
front of the speakers! On 'kind of blue'
the alt and tenor sax are 3-4 feet outside the outer edge of the speakers and I can
localize Miles' trumpet head moving when playing.
Depth is ok, the
speakers went from very front to little recessed presentation, depth is however
only 9=12 feet deep I would say. Odyssey seems to be said to be flater in depth so maybe
that's it.
so, in sum, I heard better (but on amp ~10k$). Instrument placement is much better than
at the beginning, pretty good overall I would say.
With lots of power behind them, very loud and complex passages go through
without any congestion (Epiphanies, Number 11 as example). No matter how much
bass and violins romp on the stage.

Bass: I am lost how people can make such strong statements about bass quality
unless they have very, very good listening rooms with no room modes. I did CAD
(Cara) modelling to place my speakers, still the peaks and dips below 300Hz are
unbelievable. And my room doesn't echo much, has sloped celing and is very
non-rectangular. Correcting using TacT makes the bass a completely different game!
Dimensions taughter so a kick drum can be easily told from drum/contrabass/bass guitar,
even when very loud.
Anyway, when corrected, the bass is very good and deep for a floor-stand. I measure
the speaker keeping up decently down to 20Hz and then still trying down to 10Hz.
What helped was a lot of solid state amp power, of a smaller NAD 50 or 70W amp it
sounded ok but no way as open as now. It's probaly some of the best bass I heard without subs.

Middle: very, very good but I think it's primarily the amp. Stratos seems to
be very good here as well. Female vocals/sax are outstanding.
There is one gripe I think I attribute to the m80s. There is in upper mids a
'hole' in localization where instruments seem to shift or loose localization.
I assume that the dome tweeter and mid drivers are phase-reversed (dome vs.
cone) and that flips/kills localization for the crossover frequencies (seems
we humans are doing localization via phase of mid/higher frequencies?). As well, either
my amp or Axioms do not like that much very sharply plucked instruments with
lots of harmonics (acoustic guitar). It is very good still but the 'raise-my-hair'
magic I heard on AR with 10K$ amp is not here. That's irregardless of running through
the TacT DAC, the CD's DAC and TacT ADC. Maybe the CD player has a weak spot here,
don't know.

Top: Yes, it is bright in the sense that it's almost flat, rather than rolling 3/6dB
off like lots of speakers/gear does. I verified the very flat response using measurements on
the TacT. So, the speaker is great, most recordings are however not standing
up to that much scrunity. I listen now with a 3db rollover from 300 to around
10k and then about 6db rollover to 20kHz. Only few recordings sound good
flat. The tweeter is very, very sensitive, listening over 80dB peak I hear any noise/
quantization of the CD or whatever it is on most CDs unless it's few good HDCD recording
(yes, also when driving digital toslink or 75Ohm). And on most classicals you hear page-turning,
piano player breathing, on jazz you hear the guy getting his lips on the trumpet.
Not necessarily what many people may care for.
So beware, if your recordings are not that great, Axiom will be punishing you
unless you can like me play with the target curve on a TacT to dumb things down.
Also, I think that when played very loud (>85dB peaks) the speakers starts to
emphasize the mids and highs (storing energy? enclosure vibrations?).
I can't objectively measure it but on recordings with problematic presence
region the sibilants become worse when played very loud. I can equalize the problem
away (TacT has very neat digital software equalizer) and think I will dump couple of
ten pounds of lead shot on the speaker top.

Summary: m80 and odyssey monoblocks (which I don't review here but can only highly
recommend) are a complete
_steal_ for the money and from my hearing comparisons come up with a sound close
to 20k$+ setups I listened to. With a TacT thrown in, there were few things that sounded
better I heard and all of them had hair-raising price tags on them. If you have
patience and money for esotherics like 4 speaker setups,
electrostats, ribbons, tubes and LAMM monoblocks, you can get
quite a better sound in certain areas but with no-maintainance floor-standing cones
& A A/B solid-state
the setup seems to cover way over 80% of what's possible.

BUT

i) it's a very
revealing setup, if your sound material is not that great, be sure you listen to
it first, you may realize that you don't like it anymore (I scrapped about 50% of
my most preferred CDs, they're unlistable on this setup that mercilessly reveals
faults [things like no soundstage, crappy vocals, very 'hot' mixes, too much
'playing' with soundstage]). Most 'studio' recordings in the 'pop/rock' departement
went the way of the doodoo.

ii) you need lots of room, I would say closer than 10 feet don't listen to m80s.

iii) with a lot of amp-power m80s sound much more 'airy', especially bass improves.

disclosure: no affiliation with any of the products mentioned except as happy
customer.