I have heard all of the above mentioned equipment at different times and in many different systems. There is no doubt that the JL products are exceptional, but with a properly engineered speaker, like a Rockport, they can often times take away from the overall articulation and resolution of the bass. I had two Fathoms in my system with a pair of Mira's and found that my bass performance was superior without the Fathoms in the mix. Is that the case for every room and every speaker? Probably not, but with a speaker like the Altair, which has a 15" woofer and an 8" mid-bass driver, more low-end headroom isnt always better. Really depends on what your musical tastes are, but for 99% of the people out there, what the Altair can provide standing on its own feet is more than enough. I would put the Altair up against any loudspeaker in the world, regardless of price, its really that special.