Is the Rockport Avior II an Endgame Speaker?

Here's a thorough review (listening AND measurements).  It still appears in Class A (full range) of their Recommended Speakers, along with ~30 others.  Worth the read, then you can decide which & how many others you want to check out.

If there is anything Rockport speakers do weel, it's bass response. They are bass reflex which rolls off at 24dM/octave but the designer claims and told me his speakers have a custom alignment so they roll at 12 dB/octave like a closed box. He pointed me to John Atkinson's Stereophile test and darn if it didn't drop 12 dB from 40 Hz to 20 Hz which is just like a closed box and the only time I know that occurs in a bass reflex speakers. I suspect it turns into 24 dB below 20 Hz but there's so little music down there. There's very little below 40 Hz for most music forms. Plus I have heard Rockport bass. If you heard poor bass there's something wrong in the setup which could include the room. Rockport bass is no problem, among the very best(along with the rest of their sound).

Depending how close you have them near the corners will enhance the bass 

I have owned the Rockport Atria II and Cygnus. Both are impressive speakers and I never noticed the bass being muddy with them. The Cygnus did put out a lot of bass in my room but that was easy to remedy with a bit of digital eq below 100hz. I found Rockport speakers to be extremely coherent from top to bottom. With that said I did own Magico before and missed some of the Magico sound. Since I have moved on to Estelon which I find more detailed and easier to position in a room. 

FWIW, I heard these at AXPONA this year, they were some of the best I heard and left a lasting impression. I am guessing that properly positioned in a treated room they would sound great.