I don't have either of the Salk speakers nor do I own the Cirrus. [I heard the Cirrus at Axpona 2014 and noticed a lack of the lower bass.] However, I do own a pair of Fritz LS/5-R speakers which share the Scan Speak Illuminator 5.5" midwoofer driver as the Silk speakers.
These 5.5" drivers deliver very satisfying bass levels even at very reasonable listening levels. The midrange clarity is excellent. When I show the speakers to friends and acquaintances, they cannot get over how great the bass is especially considering how small the midwoofers are.
In my (more or less) humble opinion, once we get into the Illuminator/Revelator/Audio Tech/Satori/Seas Excel level of midwoofer drivers, most of us are just splitting hairs trying to determine which one is the 'best'. Sure, they have different qualities, but I'll wager that in a truly blind listening test, most of us would be more than content with any of the configurations. I don't mean an A/B comparison - I mean if you listen to speakers A behind a curtain, you'll love them. Likewise, if you listen to speakers B, you will love them. It's only when we are presented with different packages that our eyes and our imaginations push us to lust after this or that variation.
I'm as guilty as the next guy of constantly pouring over all the eye and ear candy looking for my next pair of speakers, but when the day is done and I'm listening to my speakers, I know damned well they are really nice sounding speakers.
My suggestion to you is call Jim of Salk, Fritz of Fritz Loudspeakers, Ryan of Vapor, Rick of Selah, Klaus of Odyssey, etc. and arrange for them to send you a pair of speakers to audition for a few weeks. It's is the only sure way for you to know 100% that this or that pair of speakers suits you best. I think most of them have very reasonable return policies. Go ahead, man. Give it a try. It's what I should have done 2 years ago. You'll spend a little on shipping charges, but it's not that much in retrospect. Heck, I drove many hundreds of miles to a dozen audio shops, flew to Chicago for three days for Axpona '14, and read hundreds of reviews and spent God knows how many hours researching before I even began committing to decide
which speakers I wanted. How much money did I spend doing all that?
Enjoy your journey!