Wow.... My system is so much like yours I can't believe it. Proac D30r / Simaudio 870a / Classe preamp / Aurender / and all Nordost cables. I see that you run your speaker cable to the ribbon tweeter and jump the mid/bass driver. I tried that setup but it sounded too thin. Were you getting too much bass from the left speaker being close the the corner? I also upgraded the stock spikes to Nordost Sort Fut which made a big improvement. I am now working on taming a few bass peaks with EQ and room treatments..... You have a beautiful set-up and I bet it sounds great!
Same feeling I get after returning from auditioning loudspeakers. It is most likely because we have optimized our system and also taken great pains to place the loudspeakers in the optimal spot.
Is the smearing of the notes due to flabby bass? I noted that during the demo at AXPONA this year. Maybe it was the room. But in the demo last week, the bass was better controlled than that at AXPONA.
Currently I'm using a magnum dynalab SR100 silver ribbon antennae that goed through a magnum dynalab 205 signal sleuth amplifier to the accuphase T-1100 fm tuner. The Magnum Dynalab SR100 is the best indoor antennae I've tried, and I've tried many. I get by with an indoor antennae because my main listening station Q99.1 in Roanoke, VA has 190,000 watts of broadcast power.
I have heard the Proac D48Rs. I felt like they would have too much bass for my room geometry. I debated between the Proac D20Rs and the D30Rs and went with the larger. I will say they need a lot of break in time 500+ hrs.
I just keep coming back to your system. Can you please describe your experience with these loudspeakers? I see you have some formidable gear to go with the ProAcs. My room is so similar to yours (15 X 18 X 8). Did you hear the D48Rs, by any chance?