Sound Lab A-1 & the Ultimate differences

With a [rp[er set up, could anybody " hear " the sonic differences between the Sound Lab A-1 and the Sound Lab Ultimate ?
Perhaps if you could set them up in identical rooms with the same equipment. Other than that I think it would be pretty hard, even Soundlab admits the differences are minimal and primarily in the bottem octaves. I understand that the panels and the electronics are the same, the only difference being the frames. In theory it would sem to make a bigger difference because of the rigidity of the metal frames. Albert where are you on this one?
Bryceeboy, I went from the Soundlab A-1 to the Ultimate 1, and there was a big difference. However, in my case there were several upgrades on the Soundlab design in the interim, so my experience is inconclusive as to what did what. I agree that the two models being close is probably accurate. However, this would only be if the A-1 was ordered with the Ultimate upgrades, which include special wiring, posts, connectors, and toroidal transformers. Beyond that, the rigid nature of the steel frames should produce some performance gain, but probably not proportional to the difference in expense. The same question could be asked as to the differences in performance between the A-1 and the less expensive M-1. Each of these three Soundlab speakers, if equipped with the Ultimate power supply upgrade, are more alike than not. They share the same core, same diaphragm and radiating area. My excuse for buying the Ultimate 1, is that I love Soundlab, and having owned the others first, committed to their best model, knowing it suited me perfectly and that it represented my final purchase in a loudspeaker.
I sell Sound Labs, and have recently heard current-generation Millennium-1's (A-1 equivalents) and Ultimate-1's, with the same amplifier and source material, though in different rooms. There are differences. The Ultimates do seem to go a bit deeper in the bass, and but the main difference was in the soundstaging. The M-1's are quite decent in this department (especially in depth of image) but the ultra-rigid metal frame U-1's throw a very palpable no-room-boundaries kind of soundstage that I simply haven't heard before or since. So yes, there are real differences, which may or may not be worth the extra ten grand or so.