I owned the Studio Grands powered by a pair of Krell 300S, I sold them in fear of never being able to get support in the event something broke.
I now use a pair of Magnapan 3.6 powered by Audio research Ref 300 MkII.
The Apogees were POWERFUL, delicate and involving. They were a complete nightmare to setup - just when you thought you had them placed in their optimum place, you would move them a 1/4 of an inch and they would sound completely different. I got tired of wondering if I had the best placement.
The Magnapans sound better in some ways - maybe more relaxed and musical - but they lack the authority of the Apogee's.
I'd have to say the Studio Grands were the best sounding speakers I have ever heard (also the most work to listen to).