duegi,
If you liked the 2.3 then I can confidently say I believe you will really enjoy the CS6. The bottom end you are lacking in 2.3 you will get in spades with the CS6. They do need a little more room volume and placed off the side walls a little more than its younger sibling.. If you have the space and you dial them in you will be rewarded with a speaker that can deliver.
Get lots of power. The mid sized Krells on the used market, that have been recapped, will not disappoint. FPB 350MCX or 450MCX will pair nicely with CS6.