My vote will go to the Marantz SR5400
I was recently in the market for a receiver and auditioned at great length similarly- priced models by Marantz, Denon, Yamaha, and Onkyo Integra. For sound quality, only the Integra could approach the Marantz The Denon was not bad but unremarkable; the Yamaha -at least to my ears- sounded very muddled and compressed, the highs were poor, and soundstaging/imaging was below par; the Integra unit sounded very controlled at the bottom end and did sound quite excellent but it did not offer some key features such as 192/24 DACs for all channels and preamp outputs. I did the auditioning on newer (and poorer sounding)Polk RT towers, 500$/speaker Klipsches and some high end KEFs in the audio room at Listen Up.
The Marantz SR5400 however offers some impressive features and sounds amazing, it was an upgrade for me from a Pioneer Elite vsx-24tx and it was almost like a sonic epiphany. It finally allowed me to fully hear my speakers' potential (older Polk RT55), the electronics in my system were no longer the bottleneck.
It's highs are incredibly clear and smooth, and it's imaging in stereo is nothing short of amazing for a receiver (in my system at least).
Since I don't know what the missions sound like, I can't give absolute advice, but I would give a listen to the Marantz- not only has it been excellent so far for me but it does sound appreciably better not only in my system but also throuh 3 different speaker systems at a local HT shop.
