For you and/or anyone thinking about an M10, there is one very important caveat: if you are hoping the highly rated Sabre dac in the unit means it does cutting-edge Hi-Res, you will be in for a disappointment.
New M10 owner here. I really like my M10 but... if I had a large number of DSD files (I have some but not a lot), then I would consider looking elsewhere. The BluOs operating system for the M10 does not provide native DSD rendering- heck it handles no more than 24/192. Furthermore the BluOs team does not seem much interested in implementing this feature in the near future. Sure I can fire up Roon on my PC as a workaround but that defeats the purpose of the NAD M10 as an all-in-one audio solution. If you are a whole-home audio kind of person, then you'll have reason to enjoy using BluOs. If not, and like me, you're coming from using Roon, you will see shortcomings in BluOs- it's okay, but it's not the same experience you get with Roon.
NOW, with that said....
The impression I have of the M10 sonically is very favorable. I currently use it to drive a pair of PSB T2 Towers. These speakers have an impedance curve that indicates they need some juice despite their forgiving sensitivity. I had used a Peachtree Audio Nova 220SE prior. I have heard the PSBs driven by Krell Monoblocks in a setting outside my home (so I know how good they can sound under optimal conditions). My smallish 13x15' room is not optimal and no, I am not going to say that the M10 provides the same sound as the Krells. However, the NAD is lightyears ahead of the Peachtree in terms of tonality, soundstage, and drive. You will get told, and I so believed, that NADs have a tendency to sound a little reticent, a little too laid back. Not so with this one, it has a nice bit of kick to it. You do have to turn the volume higher than you would for other amplification to get the best sound though- I listen at moderate loudness and keep the volume at 60-70% of max. This gives me good sound whether I listen to pop, small scale jazz, or large orchestral works. I recommend it.
I hope I haven't unnecessarily put you off considering the NAD M10 but I'd hate to see anyone (say anyone with a large number of SACD rips in their collection) burned by the failure to implement native DSD in the product. Heck, I have seen a lot of info, reviews, and advertising that casually mention the Sabre dac and its specs but almost always neglect to mention that if you need DSD, the M10 will not be for you.
I do not want to scare anyone away from the M10. It is with the best of intentions that I posted my warning- trying to head off trouble for you and my fellow enthusiasts (and less importantly, secretly hoping that NAD gets wind of this issue- maybe even pressure sister company Bluesound to rectify the situation. BluOs could become very good but is still a work in progress. It has got some nice features but it has a ways to go). Before buying it would be best to audition ... I did... and purchased. So consider that.
Hope this helps.