I've had the LX-505 for about three months, set up as 7.1.4, and I am quite happy with it. I am using it for music only.
Some points - contrary to StLouisRed, I do get surround sound from HDMI inputs 1-3, this with an Oppo 105D and a Sony X800M2.
I did not find it difficult to set up, although like all equipment, it has idiosyncrasies.
One great feature - there is a listening mode "mono" which directs the audio to your center channel speaker. This is a boon for anyone who has a collection of monaural recordings. Mono recordings played through a single speaker sound substantially better than the more usual playback through the front L/R, or even worse, the horrible mono upmixed to multiple speakers. Center speaker playback is, at least for me, a lot nicer than using either the left or right.
I got excellent results with Dirac Live. I used the Dirac desktop app and a third party mic (UMIK-2). I did not bother with the built in version. There are three slots so it is possible to have filter sets with three different target curves. The only inconvenience is, if you change the speaker designations (such as switching a speaker from Top Front to Top Middle), the Dirac filters will be deleted, but if you saved your measurements they can easily be reloaded for any given set of speaker designations. I did not try the MCACC calibration at all, it conflicts with Dirac and seems pointless to me.
The "Direct" setting is excellent, it engages Dirac processing, speaker trims and the equalizer (which I found generally useless) but bypasses upmixing and other DSP processing; the AVR will decode the exact channel arrangement of the source.
There is an iPhone app that provides access to everything that the remote has and much more, including rapid access to playback from a USB device. The speaker trims setting accessed through the app are persistent, meaning they do not change, even if the unit is completely powered off (unplugged).
From my experience, this is a terrific receiver for anyone on a budget who wants Dirac Live and up to 7.1.4 or 7.2.4, and the Mono playback feature is invaluable for anyone that has a collection of monaural recordings, or, I suppose, older films with a mono soundtrack. I compared this at home with a Denon 3700 (which I returned) and an Integra (also returned).