I have had a pair of M4TM’s for a while, and they are fantastic. And I can readily compare them to the regular M4’s because mine were. And got then upgraded to the TM version. The main difference was in soundstaging and depth due I guess, to the additional back firing tweeter. The new xover seemed to have better parts quality than the previous but it did not look like a big difference. The TM versions of the M3 and M4, it seems to me, were not offered for a long period and did not get a chance to be thoroughly reviewed and appreciated. I drive these with Pass and First Watt amplification and being a nominal 12 ohm impedance -TM’s were supposedly optimized for SE amps.- maybe is not optimal but the combination is superb, anyway. I’ve seen a few offered for sale and that would be a grand opportunity to get into the Spatial sound at a reasonable cost. I have pondered getting a pair of Saphire M5’s but wonder if it would be a real upgrade. And, due to their weight it would be very costly to ship them to where si live. So keep enjoying your M4 TM’s Rob.