I’m not going to be able to answer your questions, but I’ll try to help, even though you may also not like my answers. :)
First of all, Wilson needs A LOT of space to sound very good. I owned the Yvette, and they were very easy to love. Unfortunately, I had to let them go because I learned I could not give them enough room. My room size? 18x23, with a sloped ceiling that went up to 18 feet. Despite the room size, I could only have 3-3.5ft behind the speakers (whereas speaker baffles were 5’ from the wall). With the speakers rated down to 20Hz, it added a bit of congestion. I learned after that the Yvette sounded best with at least 5-6’ between the back of the speaker and the wall.
So my first suggestion is to not go with the Yvette as you will likely not have the room to bring the best out of them.
The Sabrina X on the other hand, is known to have a bit of added midbass bloom to make it sound like a “grown up” speaker compared to its bigger siblings. Whether that is something you enjoy is your call.
The Sabrina X does have newer technologies and design principles and the way they have been updated from the previous version does make them sound much better - better imaging, more resolving. The Yvette has not been updated since it’s release and uses older drivers, damping, etc.
If you can find the Sabrina X at an accessible price point and are able to demo it and enjoy it, that would be my recommendation, or look at other speakers that may be a better fit for the room.