Hmm… turns out I can now (to some extent) answer my own question, as I have now tried all these saddles. My favorite County saddle remains the Stabilizer/Stabilizer XTR, followed by the Solution H/J (I’ve not tried the Solution monoflap).
@cleozowner Did you also try a Stabilizer? It doesn’t really matter, but if you did, that will give you a closer idea to what a Conquest feels like. It is different than a Stabilizer, but closer to that than the others. The Conquest is built on the Stabilizer tree (but interestingly, my other mare strongly preferred the Conquest to the Stabilizer… so clearly, there is far more to all of it than just the tree). Both the Stabilizer and the Conquest have been discontinued.
County currently builds on two trees - the Innovation tree and the Sensation tree. The Solution is typically built on a Sensation tree for the narrower widths (through medium) and an Innovation tree for the wider widths (wide and up), but can be (or at least could be) custom-ordered on either tree. The Solution is apparently a bit of a deeper seat than the Sensation, but they are supposedly more similar to each other than the Innovation, which has a shorter balance point (all this is per County).
The horse for whom I was saddle-hunting did not appreciate the Sensation, so it was ruled out for that reason. For me, as a rider, I felt very far away from the horse, and for some reason the saddle seemed to make me pinch at the knee (which is not usual for me). I think the Whippy panels (standard on the Sensation) may have been the problem, at least for the horse.
I personally hate every Innovation I’ve ever sat in. Something about that saddle, regardless of seat size and regardless of the horse it was on, just doesn’t work for me. I feel stuck in the backseat, and posting without stirrups and two-pointing is remarkably difficult in that saddle; put me in basically any other saddle in the world, and those two things become much easier. But I know a lot of people like them, so maybe it’s just me.
I came very close to laying down the money for a Solution (built on a wide Sensation tree), but ultimately decided that it was just too much money, and what I needed was not available on the demo/used market. I would still consider one in the future. This one felt a bit wide in the twist, but it was what made the horse happiest of the County lineup, so I was willing to deal with that (I also think it’s just the nature of having a wide horse… it’s very difficult to have a truly narrow twist on a wide saddle, and twist width doesn’t usually bother me).