I own the Sasons and love them, but have spoken many many times to Dale about the Summits too. They are, as you said, both very very good speakers with very little ad or review momentum, and the designers are top notch customer-focused folks. RSA's Steve Rothermel set mine up at my house and although they take literally weeks (45-60 days of constant signal) to break in (and sound like crap unitl then), they sing from 35hz and up, and are the most transparent transducers I've ever heard. The lowest registers are dialed in via a Velodyne SMS-1 and a PAradigm Servo 15. Steve and Robert have plans for other speakers in the line, inclding a sub someday.
What is your system made up of, and room dimensions? The Sasons would love to have considerable room from the front wall, and breathing room from the sides is beneficial also. Dr Hoover has his Summits closer to his front wall and his getting great results. Now that mine are well broken in (October 06), I may experiment with putting them closer (but I'll mark the floor in detail before I do...they are great in their current spot 7 ft out into the room).
Ted