Sure, no problem.
I have been extremely satisfied with it's sonic performance. It sounds very neutral, but without being fatiguing. So far, I have only used it with PCM, as my library is currently a mess and being redone, so I haven't bothered getting any DSD tracks yet. I'll probably get the SACD Beach Boys releases sometime soon though. For PCM, I've mainly been using the Slow Response filter (the default), but I've been playing with the minimum phase filter as well.
My main headphones are Sennheiser HD 700's, and I've found the m920 to work well with them (hell, the product picture on Grace's site shows an HD 700 cable connected to the m920), though it is worth noting that I use my Woo WA7 (currently stock tubes, but I plan to try the upgrades eventually) as my primary headphone amp. In comparison, the m920's main difference is being more neutral and having more high-frequency extension (something the upgrade tubes for the WA7 are supposed to improve). The HD 700's are known for sometimes being a bit treble-heavy, and so far I haven't had any complaints. It is worth noting that once the volume of the headphone amp hits 96.5, the volume attenuator adds 10dB of gain (and brings the attenuation down by 9.5dB), which does add some noise (hiss), but I can't hear it with my HD 700's. I can only hear it when I use my SE 535's, which I don't really use at home anyways. The attenuator chip is a Cirrus Logic CS3318 as mentioned earlier in this thread for anyone interested.
I mainly use the m920 as a standalone DAC (with the single-ended outputs in standalone DAC mode), which feeds both my WA7 as mentioned above, as well as a NAD D 3020, which powers a pair of CEntrance MasterClass 2504's. I'll be honest and say that I don't have a ton of experience with high-end DAC's, but I certainly noticed an improvement over the one built into the WA7. The first improvement I noticed when I upgraded was the sound stage. It felt easier to "feel" where something was coming from (again, sorry if I'm not the best at explaining these things).
As far as fit and finish goes, I am extremely impressed. The looks speak for themselves, and as I said above, in addition to the obvious, I love the Grace logo on the top as well as how the top and bottom plates have an angled cut near the front panel. The m920 is built largely (if not mainly) as a piece of studio gear, so its looks are plain, but in a way that feels premium. All edges are smooth, although the edge around the display is a bit on the sharp side (but this is nitpicking to extreme levels; it's not like it's sharp enough to even consider cutting something or someone). There is no play at all in the source selector, and it has a nice click to it when moving it. The volume knob has a VERY tiny amount of play in it, but again, this is nitpicking. The controls are extremely easy to use (though you will need the reference manual to know what is what until you memorize it from normal use, or at least the settings you may find yourself changing semi-regularly). The menu will remember what setting you were on when you left it, even if the unit has been power-cycled. It is worth noting that there are a few more hidden things not mentioned in the manual: holding the volume encoder while powering up with the source selector not set to USB will show the firmware version installed before booting up if released at around 2 seconds after powering up, or if held longer will do a display test, turning on all lights and display segments until the unit is power-cycled. If the volume encoder is held down while powering up with the source selector set to USB, the unit will give you the option to reset all of its settings to the factory defaults.
The only thing on the m920 that I think could use a minor improvement is the standalone DAC feature. I'm somewhat surprised that it can only be used on the single-ended outputs. In addition to this, in order to enable/disable the feature, jumpers inside of the unit need to be adjusted. This isn't a setting you're likely to need to change often, so it's hardly a big deal, but I think it's worth mentioning. Even if it was too complicated to allow control of this via the menu, I think some hidden dip switches would've made more sense (heck, even if the internal jumpers were replaced with dip switches). I can't imagine this being a big deal for 99.9% of people, but I suppose if you are in that 0.1%, you could make yourself a switch to attach to the jumper pins. I do like the fact that Grace shows that they don't mind people opening their gear and taking a look inside. Lastly, you should know that when using standalone DAC mode on the single-ended outputs, no volume or volume related controls such as balance will work for the single-ended outputs (as is the point of the feature in the first place), and the analog inputs will not be passed to the single-ended output, which makes sense, as using something as a standalone DAC implies that you're not using it as a preamp.
. I especially love the way they brand the top of the unit as seen here: http://headphone.guru/wp-content/uploads/2014/11/Grace-m920-1-of-9.jpeg (for anyone interested, the colors in this picture are a bit off, as the display and power button illumination are pure white, while this picture makes them look a bit blue).
