First of all, the sound is much better than with the Pioneer I had to replace, surely because of the higher output specs. This might also be because of some processing to allow full surround feeling even at lower levels that I'm using. I had this on an older, non-HDMI Pioneer that I loved, and they called the setting Midnight IIRC. A very useful effect when you have small children and live in an apartment and wanna watch action movies and thrillers in the evenings.
The GUI in this Sony is very nice actually. If the GUI in my Pioneer was Windows 3.1, this is at least Windows XP in comparison. It has an HTPCish layout, you assign each input with a tag (watch, Game, listen watch/listen/) meaning that when you start it up, you will have a HOME menu (the remote even has a HOME button) with WATCH, LISTEN, GAME, SETTINGS almost like in MePo or XBMC. When you click one, the inputs assigned to each category are presented. You also have two Watch and Listen buttons on the remote for quicker access. The remote isn't at all cluttered with buttons because of this though, you only have these buttons:
HDMI INPUT | ON/OFF <-Not sure what HDMI input does as I haven't had time to explore all options yet, but I think it just cycles the inputs BD/DVD | SAT/CATV | GAME
SA-CD/CD | USB | TV
WATCH | LISTEN | TUNER
Custom preset: 1 | 2 | 3 <- Not really sure what these presets are for yet, probably shortcuts for your most used inputs? A.F.D./2CH* | MOVIE | MUSIC (*A.F.D. is Sony's abbreviation for Pure Direct (no effect on the sound) <- These buttons cycle through all the available DSP effects
Display | AMP menu <-Brings up these menus
-- Arrow keys and OK button here -- Return | Options <-Brings up these menus
HOME <-Takes you to home screen Skip left | Play/Pause | Skip right
Mute | Volume up
Sure, I will miss not being able to control my Panasonic TV with the Sony remote (I haven't tried the CEC HDMI option yet though, really miss not having a proper manual for stuff like this so I can just read up on it, I will check out Sony's site when I have finished writing this review or what you'd call it) - the Pioneer did this really well with their remote, I used it for Blu-Ray player and TV actually, but I like the simplicity of this remote - less is more IMHO.
Furthermore, with the GUI being overlayed on top of the the input video, the volume buttons bring up an overlay so even if you can't see your amplifier, you will still see that the remote has contact and is working (if your TV is on of course ). I like this a lot, not sure if it can be turned off though.
The mobile app is decent too, I have an iPhone, and browsing my Synology NAS' indexed media files is pretty quick. With the Pioneer app for iOS, when I had scrolled down to the letter V in Album Artists, it was displayed as Unknown artist for at least five seconds. In the Sony, I can see each artist name immediately without lag. With the Pioneer, I used a LAN cable to connect it to my network, the Sony has built in Wi-Fi, so I guess the Pioneer was just slow all the way.
Playing back FLAC files through the APP (or browsing the NAS using the receiver's remote) worked without problems. There's a "wav" icon displayed for some reason with FLAC playback, so maybe it's decoded to PCM first, but I didn't notice any delays when switching from one song to another.
I haven't been able to playback video files, mostly because I'm not sure what formats are supported. Nor have I tried browsing pictures in it as of yet. I will continue to explore this receiver the coming week (as time permits) and might post a follow up if something truly significant presents itself.