The Sig Ser. models are upgraded. Both have blue LED readouts, Polished & curved face design, Upgraded power cord to the Powerline 400.
The 7000ss has a T2 auto reset function after a large ac surge (the standard 7000 needs to be sent in to monster to have the unit reset or repaired)
7000ss also has a dual noise reduction mode w/switchable balanced & isolation mode, & a voltage & current indicators. The AVS2000ss dosnt really have a big improvement over the AVS2000 but the HTPS7000 dose. We were going to keep the AVS2000 but it wouldnt match with the HTPS7000ss once we stacked the units, one would have a black face which is flat & the ss has a polished curved face. May be not the best reason to upgrade the AVS2000 but we use our system for demos & I want it to look good as good as it preformes.