just something to share... I purchased the 5LS mostly due to the positive comments from other users in this thread! Thanks for all of the contributions!
My previous set of speakers were Ref 3.0. Obviously jumping from 3.0 to 5LS is a significant upgrade; furthermore, it is my very first experience with line source speakers, which are quite rare in the market.
5LS is definitely a lot harder to set up than the 3.0, and requires very demanding audio equipments, which I was not expecting. Now I am seriously considering to Bi-amp it with another set of nCore400.
I am only using the 5LS for music play back, thus I cannot comment how well it performs with movies or with AV receivers. But I can imagine you will need some very powerful class A amps to drive it properly, especially for the bass woofers. It has a relatively high sensitivity but somehow it is irrelevant. My friend has warned me line source speakers requires very high end/professional set ups to drive them properly (and often times those equipments will cost a few times more than the speakers), I guess I do understand now. Positioning the speakers is the most challenging/frustrating part - even a few mm of turning will affect the imaging greatly.
The major differences between 3.0 and 5LS are imaging, accurate positing, separation between instruments in orchestra music or live recordings, and very dynamic type of sound. The bass quantity is less than the 3.0-3.5, but it has a hell lot more details/layers in them. I believe only bi-amping can release the full potential of the bass section.
I had my doubts with 5LS because there were basically no constructive reviews by any major magazines nor blogs like 6moons - I guess either Anthony knew the media can't set them up properly for a positive review or the fact that it is simply too tall to move into the elevators or 5LS has an identity crises of targeting the proper consumers.
So here you go, i personally recommends potential buyers of 5LS to audit the 3.5 first - because it will easily work very well with your current or future audio equipments. If you are going to 5LS, you are opening a can of worms... you have been warned!