So, I finally got a chance to do some critical listening to the UHFS upgrade in our MX, so I thought I would share some thoughts. Background: I am an audio-enthusiast (never liked the term audiophile). My main audio rig is an Spectral/Avalon Acoustics set-up, which is sadly crated in the garage these days (lack of time and space). Material: For the initial listening I used three albums: Waltz for Debbie (Bill Evans Trio), Eric Clapton Unplugged, and Come Away With Me (Norah Jones). Music files were 192/24 FLAC fed of a USB stick, which essentially means they were very high resolution and delivered to the UHFS uncompressed (more on that later). I then went back and listen to a couple more albums to see how the system did with different genres: Jekyll + Hyde (Zac Brown), Night Moves (Bob Segar), and We Sing, We Dance, We Steal Things (Jason Mraz) also off USB, but these were at standard/Mastered for iTunes files (NOTE: I am not going to wade into the battle on if there is an audible difference between the two formats). Environment: MX P90D, six seat edition, doors closed, windows up, all seats up, climate control off, and vehicle stationary. Dolby Surround is off. Unfortunately, I have not heard the standard MX system, so cannot offer a comparison, but I can compare it to the Studio Sound system in our MS. To cut to the chase, I am pleased with the upgrade for the following reasons: Tonal balance--highs were crisp without being overly bright, the mid-range was full and smooth (did a nice job with Norah Jones' voice) and the bass was powerful but tight. Personally, I am not a big fan of rattling the neighbors windows if it ends up making the sound muddy--hard to do without big cones and big amps. Sound stage--can pick out individual locations of singers and instruments--everything is not concentrated in one amorphous blob, the soundstage was open and airy Resolution/Texture--this is a hard one to describe. Think of the difference between a low resolution pic of a dog and a high resolution pic of the same dog. In both pics you can tell its a dog, but many more details and nuances emerge in the high-res pic. The same is true of a good audio system that will reveal the nuances of a voice or an instrument. I was pleasantly surprised by this as its quite hard to do. Doing back-to-back listening vs the Studio Sound system in my P85, I found the following differences: The tonal quality is different--can really call it better or worse, just different Soundstage was less distinct and more compressed Definite loss of resolution/texture The Studio Sound is still quite good, but the UHFS is noticeably better. So, now the caveats: Listening tests are always dependent on the material--I used music that I listen to. If you listen to hip-hop or chamber music, you might end up with different results (although I would venture the system will do well with classical music in general). All my material was uncompressed. If you primarily listen to compressed sources like XM or stream music over Bluetooth, its going to impact music quality. Slacker seems to be highly variable for me--sometimes is sounds great, sometimes it sounds like AM radio (I have the LTE upgrade and have the Slacker app set for high quality).