Again, and again, and again ... it's all Symphonic Line. The Stratos, Tempest etc. And unlike most other companies, with SL it's definitely the "more you pay the more you'll get" kind of deal.
Yes, I'm incredibly proud of the Collossus upgrade of the monos, but on the other hand, I have to be honest and state that the RG 4's are indeed the better amps, as they should be for the extra $$$. Now, with the Krafts, all bets are off.