The Ushers are rather sensitive to room placement. And I would not say the mid-bass is overblown, but i might suggest the upperbass/lower midrange might be with certain placements.
I have 718s, non-BE, and my experience is that, in a room that is reasonably flat, they are reasonably linear. Somewhee around 250Hz, they might have a little more energy than they need to, but otherwise? Not really.
As for not using tubes with them? also not true at all. I've used the Antique Sound Lab ASL AQ-1003, the Hurricanes, a Cayin (not enough power, of course) and Arcam FMJ A-22, a Vincent SV-236 (or whatever that model number was) and found them very good. The areas where they are not state-of-the art:
microdynamics: a little slow in the 718s. Perhaps the BE version improved it, which would be likely, as the tweeter determines the micrdynamic abilities of a speaker. For example, a Mirage 490, with a Titanium dome tweeter, fed by an Arcam Alpha 9, JVC XL Z-1010TN, MIT interconnects, a la 1994, Transparent (1993 generation) speaker cables, has much greater microdynamics than the Usher 718, which has Transparent MM2 speaker cables, Nordost Valhalla inteconnects, Rega, Cambridge, JVC or Meridian CD players. The tweeter is a significant determining factor in realism. I cannot imagine the Ushers sounding quite as poor as Audiofeil says, but I do not know his room. Mine as only a 1 db deviation until somewhere around 80Hz using Stereophile's Test CD. Perhaps in between the frequencies they use it isn't, but otherwise it has good octave-to-octave balance.
I've heard the Usher sound overly warm, but that is not due to tubes: that's just plain wrong. It does not have a particularly low noise floor, but to remind people of Rick Fryer's observations years ago, " transparency decreases as power requirements ASCEND." The Ushers are not sensitive at all, being around 84-85db efficient. This can make them sound somewhat less liquid than some other speakers, but they're certainly not bad at this. However, with the Cambridge 840, I was actually able to hear the floor in some recordings with the ASL 1003, but couldn't hear it withe the Arcam FMJ A-22. They're revealing enough of changes in equipment, which is not indicative of a poor equipment.
I believe it to be a good speaker (the 718), but I imagine the BE version is better.