Would you consider the LE Cygnus a big and worthwhile upgrade ( I listen to mostly R&B and pop music) from the original Cygnus ? I love the original one but found the BK to neutral for my tastes....
Original Cygnus is already really good, thus doubling the price for Cygnus LE will not give you double the SQ. In that sense, I'll say no, it is not by any measure a 'big' upgrade. Besides, as I have said, the sound signature on Cygnus LE is quite different from Cygnus and BK, so there isn't a 'direct upgrade' either, you will probably have to listen for yourself to know whether this new sound is for you or not.