With the $100 discount on the CMT-340SEs right now, that is a really good deal IMO. To me, the Ascends don't do anything wrong, but they aren't the most lively speakers. They are flat to the point that they could easily be used for mixing in a studio IMO, and that is not a bad thing (and I know there are people who do use them for this). I have heard few speakers in their price range that are as clean and clear sounding. You would have to spend more to get something equally as good, IMO. The down side of highly detailed speakers like these is, bad recordings will become painfully obvious. Good recordings will be worth it though

Detail and clarity, especially in the midrange, are the key points here.
The SVSs are lower in sensitivity and are a bit laid back. They are just short of neutral on the soft side, but have plenty of detail. Because of this, they seemed to do well in all areas; movies or music, they handled everything I threw at them. That laid back nature doesn't appeal to everyone, though I do tend to prefer a warmer sounding speaker like this. They aren't the most attractive speakers, but they feel really well built, just like everything from SVS. An even-handed handling of most material is the highlight here.
Just my opinions. How big is your room and what will you be powering them with? Is this more for movies or music? If music, I'd lean toward the Ascends.