OK, so you know what's going on then. Cabinets and drivers have gotten a bit smaller but more rigid and give better frequency response and less distortion. Efficiency is down but big-ass power amps are the norm (525W continuous in your sub) and make up for the lower efficiency to give the same SPLs you used to see with VOTTs.
No joke, you might end up needing 2 of the SVS PC+ to keep up with M80s in a large room. I have M60s and the same 20-39PC+ (real nice, isn't it ?) and in my current room that combination will play WAY louder than I want.
Of course the other option is to get another pair of VOTTs... Altec put them back into production recently, $4,300 US each :
http://www.alteclansing.com/legacy/specs.asp
Note that the A7 is a few dB more efficient than the M80 but the M80 can handle twice the power (and apparently is very conservatively rated) so the result is about the same SPL in practice although you do need a bigger amp for the M80s.
