The CS5 is a very old design using not the latest drivers, caps, resistors, wire, etc. etc. Any of the speakers I mentioned would kill it. Comparing an outdated old speaker to newer speakers is ignorant. Check out the reviews on the Ulfberht......one guy thought it was better than his big Wilsons.....and these are $9000 delivered and 98 db sensitive. No big current doubling into 2 ohm amps needed. Sorry, low impedance speakers are silly....even the latest most expensive ones....simply silly. When you can get moderately priced super transparent and easy to drive speakers under $10K.....these giant current hogging speakers are like an old model T. May they rest in peace.
I am not saying the latest Wilsons, etc. do not sound good. Its just that you have to be super rich to buy them and buy a super expensive high current amp to drive them (Parasound JC-1s are not even in the running for transparency in the $2K range today, however, they do make a fine bass amp) . Save your money. Give the money saved to those that need it. Do you think it makes "sense" to spend lots of money on super expensive current hogging speakers and super expensive current producing amps when you can get as good or better sound with way less expensive high sensitivity speakers and reasonably priced amps? Maybe you have a different "sense" than me.