From auditions many years back, so possibly imperfectly recalled:
To my ear, there were a lot of similarities between the two speakers from the mid-band up. I never A-B'd them side by side, but my sense was that both were similarly satisfying on vocals, horns, strings, etc. Obviously, the ET had more extended bass via the dynamic woofer, but there was some doubt in my mind about the broad region of two octaves (or so) between the upper bass and mids. Somewhere in there, the cross-over from the panel to the dynamic woofer took place. It's been a while, so I'm reluctant to be specific - I just had a question whether the panel/woofer integration was entirely successful.
The addition of a pair of 12" Rythmik subs to MMGs was a different story entirely:
First, I cross at 75hz which is low enough to get any x-over related issues out of the ear's most sensitive range. I'm not sure where the LFT crosses, but I'd guess it's an octave (or more) higher than my set-up.
Second, this combo represents some very serious deep bass capabilities - no question in my mind that the MMG/Rythmik combo was easily better for the kick drum region down to the lowest musical bass range (and HT range, too - tho I wasn't going to use the system for that).
Third, the Rythmiks allow electronically adjustable damping which - to my ear - further allows a more precise matching of panel and cone.
Most importantly, the whole thing was much cleaner to my ear. The LFT kinda made me wonder about a two octave range while the Rythmik (crossed via Audyssey) was just seamless top to bottom to my ear. Remember, Audyssey provides room correction, too - which cleans up the bottom octaves in a way that I like a lot.
If you're willing to use a digital cross-over/room correction device like Audyssey, I think the Rythmik/MMG combo represents monster potential for the dollar. Some of the issues that I had with the LFT might also benefit from Audyssey, but my gut sense is that it probably still lags due to the higher x-over point and more limited woofer capabilities. If you're not willing to consider Audyssey (or similar), then I can't really say which is likely more satisfying.
BTW, At the time, the cost of the two speaker alternatives was very close (within a $100 or so). I'm not sure if that's still true.