OK, a quick update:
Got out and did some more listening. I figured we would go listen to the B&W 683s since I really don't want to spend the $7 - 8k on the CM8 surround setup.
We went to a high end HT store but they seemed to focus more on complete HT design/build and not so much on retail sales. The experience started out very disappointing as the guy helping us basically set us up in a very narrow alcove in their store with a pair of B&W 683s and 2 kitchen-type chairs (there were 3 of us). After standing there listening for a few minutes, I kicked my wife out of the chair and we took turns sitting and listening (I am only semi-joking about kicking her out - but it was not fun having to switch off).
The speakers did not sound that great but I attributed that to listening in an 8' wide space with 8' ceiling and a lot of drywall. We asked if we could listen to them in one of their dedicated listening rooms. The answer was that those rooms had all the speakers in-wall and no way to change them out. This seemed very odd and I was getting pretty mad.
(The other stores I had been to years ago last time I bought new gear all had dedicated rooms where they were happy to do A/B tests and swap in and out a lot of equipment. Was I being screwed with, or is this just how stores operate now?)
The other thing I was unhappy about was that the sales guy complained about the hard rock CD I had (Social Distortion, 1 of 10 CDs of a wide variety of music) was too dense of music to sound good. Whether true or not, I wanted to see what it sounded like. He popped it out and put on an iPod with Diane Krall on it (at who knows what bit rate). So we compromised by putting on Lloyd Cole (great male vocals, very clear and clean). That also didn't sound that great and my wife leaned over and said that honestly she didn't think it sounded any better than the old Cambridge Soundworks bookshelf speakers we have sitting around. I agreed. Again, I think it was the room or maybe equipment or cabling issue. One of the speakers did have a loose connection but seemed OK that way after jiggling it.
Whether you like B&Ws or not, this should sound odd to you, and it certainly did to us.
So we tried a pair of PSB Imagine T6s next. Much the same results, so it wasn't just the B&W speakers.
The salesman suggested the PSB Imagine Ts, so although discouraged we figured we were already there so why not? The price was less than the B&W CM8s.
To our surprise, he had them already hooked up in a much nicer area of the store that had actual upholstered furniture and not crammed into a corner. (We still weren't allowed into the listening rooms.)
In went the requisite Diane Krall (I didn't try to fight that one as we do own a couple of her albums). The speaker sounded WAY better and I thought to myself OK this is much more like what I was expecting to hear. I could easily live with those
Then I noticed that the B&W CM8s were sitting right next to the Imagine Ts and began to not just suspect but to believe that we were being treated like slum dwellers for looking at the 683s and Imagine T6s.
We gave those a whirl (Diane Krall again so as not to upset the guy) and were really digging them to the point where we were seriously considering spending the extra money on a surround system based on them.
Then my wife pointed out that another customer appeared to be listening to music in, wait for it, one of the listening rooms.
There were a lot of other issues during our visit, such as no subwoofer being available to pair with any of those speakers (they thought it was an issue with the sub itself, but later said it was the cable, so 2 bad cables at their store for what I would consider mid-high end speakers).
One thing I did learn though - my ears like having a separate mid and not just 2 woofers. The CM8s were the only ones that did, and may have been the difference maker between those and the Imagine Ts.
Anyway, the guy said their other store had a CM8-based surround system (not the full CM8 system) set up so we went to look at it the next day. It was very nice (and had a working sub!).
Given that the CM8 system with CM1 or CM5 bookshelf speakers for the surrounds is quite pricey, we discussed options for those. The salesman was much more helpful that day, I mean REALLY helpful. Not sure what happened the first day or if what I described above is just "normal".
One option is the B&W DS3 dipole speaker (switchable to monopole), but they did not have any on hand to listen to.
So this would be a bit of a flyer in terms of not being able to listen but from other reading seems like it would be a great choice for a surround with the CM8s. (Actually, it is part of the 600 series as obviously are the 683s. The tweeter is aluminum in the DS3, and so a better match than some of their cheaper speakers with a non-metal tweeter.)
So we priced out a system with the CM8s and DS3s, but it is a rather large number.
Still going back and forth in my mind, but the wife really liked the CM8s and is OK with the price.
But Aperion has the Verus Grand Towers system on sale for about half the price and free shipping both ways so I may give that a try.