I've not heard the Montana speakers, but do own the tweeter that they use in their full line, the Scanspeak Reveleator 9900 (the designer told me they use a 4 ohm version). It has a combination of smoothness, speed, and dynamic contrast (both micro and macro), that no other tweeter of any type has, IMO. I also have the Morel MDT-33, and it trades off being barely not as smooth/liquid, for noticeably more dynamic contrast and authority. They're both better than the Dynaudio Esotar IMHO, which was so forceful that it imparted a "steely" character to attack transients, in the test project I'm working on. I've not heard Quads, but have heard ML's and Soundlabs. IMO, if you want to listen at quieter than lifelike levels, esl's are absolutely the way to go. Nothing comes alive at quiet levels like a good esl. If you demand liflike SPL's, a big cone/dome speaker is the way to go. In my experience, ESL panels turn hard and have a plastic coloration, even at moderate levels...where a very good dome tweeter sounds perfect, all the way up to as loud as it can go. Ribbons are very nice also, but trade off some dynamics, for unbelievable speed. And of course, if you have domes/cones several in series parallel, like the Pipedreams (or like one of the projects I'm planning), that can be "otherworldly", IMO. I've not heard the smallest Pipedreams system, but perhaps you should give it a listen...There's not a thing wrong with having the low bass speakers in a separate enclosure, that's how most of the world class speaker systems do it, and it allows the ultimate in low frequency extension, room loading and smoothness.