The M3v4 is more enjoyable than my old M80v2. That may sound surprising given the mid-range on the M80 but I place high weight on expanse of soundstage and imaging. Mid-bass is also better. I also find the M3v4 soundstage integrates into my rooms better. In fact, the less drivers, the easier and better the soundstage room integration. The bookshelves also acoustically disappear better than the larger speakers. Interestingly enough, the M50s are very good at disappearing and are also very good with the bass because they are more linear down low than the M3v4 and M5HPv4. You can see the M3 and M5 both have a low Q bump at around 100Hz and the M50 is flat. The bass depends on room size though. In my largish basement, the M3 and M5 are well-behaved in the bass. Not so in my other rooms including the living room.
Between the M50v4 and M3v4, all other things being equal, I'd take the M50. Note though both the M3 and M50 are more "laid back", less "analytical" than all other Axioms. This is due to the lack of the dedicated mid-range driver(s). Some actually like this a lot. I certainly do at times and wish there was some way to switch modes from analytical/detailed to mellow/laid back.
