Hi Jayman, Welcome back.
I have used the Elite VSX-56Txi in a surround setup with both the Sapphire 25th edition and the Sapphire XLs. The 56 has the same power ratings as the 52/54 but somewhat different processing. It was a great match. I purchased the 56TXi because I felt that while some other brands had slight feature advantages, the Pioneer sounded better most of the time.
The Elite receivers have really fine amplification. Pioneer uses all MOSFETs and very large power supplies and caps in the Elite series products. It easily played the Sapphires louder than I would ever use them in my 2 bedroom apartment, and as the Panoramas are a bit more sensitive than the Sapphires it should be great for them too.
I felt that the Elite receivers tended towards a slightly warmer sound than Yamaha or Denon, which sounds like what you are looking for. I do think that it might be a tight squeeze putting Panoramas all around in a room that size, but the Pioneer receivers all have built in room equalization, so a set up using larger speakers in front and perhaps Emeralds in the rear might be a good solution.