The newest line of Synergy is a large improvement to the old lineup. I also feel the difference in performance between the F1 and the F2 far exceeds the difference in price.
Nevertheless, the SF-1 is still an improvement to the Quintets. Are you looking for a long term purchase or are you thinking about possibly upgrading again in the future?
It's hard to make judgement calls for someone you don't know much about, but I would describe the difference between the SF-1 and the F2 as "Yea, this is better than the Quintets" to "Wow, these speakers are awesome".
-Mike Bentz
~It's all about compromise~
"Crown, Active, and Horns"