After considerable research I bought Emerald Physics KCIIs which are open baffle (and considerably smaller ~ 43" tall: 93dB efficient, but can handle big power. I find them similarly open and fast, a touch warmer sounding than the 3.5s.
I gave up trying to use the subs, still, they sound terrific, especially with my EVS 1200 class D amp (600wpc!). They can be a bit overwhelmed with large scale music in MY ROOM, which is 2+xs bigger than yours. EP was running a special at the time, including a BOM (bass management device), but the BOM did not solve the subwoofer integration problem either.
Right now EP is running a factory direct sale with carbon fiber woofers, which should be killer. Price, delivery included, is $1999. That is an amazing bargain
hth