hey nobnewob, unfortunately you will find a lot of people on this site that can be arrogant and condescending. Also, many people will tend to push an idea or product because they own and like that direction, or be anti-product in the case with stringeen bad mouthing McIntosh. I will agree that the Yamaha receiver is definitely a weak link in your system. However, I don't think the Rotel amp is too terribly bad. As with all different preferences, some will like McIntosh and others will not.
That suggestion for a Pass Labs integrated may be a good one. Reno HiFi has an INT250 for $9k, which is above your budget. It's basically an X250.8 amp combined with a XP-10 preamp in one chassis. You could look at INT60 or INT150 (essentially an older X150.5 amp I think). If it were me, I would still stay with a higher power amp for those large Wilson speakers. Wilson Audio speakers tend to be very high resolution and very revealing, so in my opinion, you have to be careful about matching. I would avoid anything too solid state (i.e. Hegel, Gryphon, etc.). Wilson can be a little fatiguing to listen to if your electronics are too solid state, but they can sound excellent with the proper stuff. Pass Labs amplifiers are very high resolution, but they are a smooth and controlled sound - great match with the overly dynamic Wilson. A McIntosh integrated could be good as well because they are mild and laid back sounding, but still have a very engaging sound.
The Rotel amp is very nice and is just a little bit on the warm side of sound. It's just a little bit solid state sounding, but it's really not bad at all. I was very impressed with Rotel when I heard it at RMAF. A switch to Pass Labs or McIntosh amps will likely be much smoother but also sound a little different in their unique ways.
A Krell K-300i integrated might be nice because the new Krell sound is VERY smoothed over and lush. Could be a good match with the Wilson's and the K-300i is $7k new. Though it is only 150 watts per channel. Alternatively, you could go used here. There's a used Krell Duo 300 on audiogon for $5k. Make him an offer for $4500? Then spend the difference on a preamp of your choice (Parasound JC2, Plinius, McIntosh?). Lot's of options.
