@simonmoon In my experience and via my dealer etc, Wilson and D’Agostino are two very good matches for Wilson. I have the Sabrina X with a MA8950. I was split between the 803 D4 and the Sabrina X. I strongly went in planning to go 803 but the Sabrina X blew it out of the water. The McIntosh has a lot of power which is what the Wilson’s want. Wilson will often demo their speakers using McIntosh Amps. Cables matters as well. Wilson uses Transparent Cable internally and often for demo's.
Based on how highly the Sabrina X is reviewed, I would make sure the setup at your dealer was ideal. The Sabrina definitely goes lower than the 803 since it has an 8in woofer vs 7in in the 803. I also found the 803 tweeter to be very harsh to the point I wanted to turn it off. Maybe listen at another dealer or have them check the setup. I should add that I listened to the 803’s at multiple dealers and all the same had meh sound. I also own the 805’s (pre-diamond tweeter). It's likely all personal preference though to our own ears :)