@ghasley I did have a chance to evaluate the Grimm MU1 in a more relaxing place (my home). Here is my summary if anyone is interested. I am not good at audiophile descriptions so please bear with me. First and foremost, the best output is AES, I used a Shunyata Omega. It probably does not make sense for most but this was the only one I had access to (from my friend). The only other AES cable I had was an Amazon basics cable. Yes I heard a clear difference between the two (do not want “cable makes difference or not argument” so ignore this if you do not agree).
Now to the Grimm Mu1. The sound is sublime, I know the term is very vague. There is no question that it brings out more resolution. I was really surprised as I did not think the digital files had anymore info to be extracted. There is a higher level of detail in every single instrument that the difference is obvious. The tone and timbre is precise and beautiful. There is simply more detail and delicacy at the top end. The mids are precisely laid out, touch more vocal forward. The lows are amazing, well rounded, firm, deep and this is where one is going to appreciate a difference without even going back and forth. I am not much into soundstaging but the staging is precise, everything well laid out. Overall sound is very detailed and engaging/pleasing. As far as oversampling, the Grimm is miles better than Roon and surprisingly it is also better than hqplayer. But I found some recordings significantly better with over sampling and some NOS mode. I can keep elaborating but I am not trying to review.
Something’s to watch out if you are looking at Grimm MU1. No streamer is perfect for everyone. So is Grimm. It does not have Wi-Fi. It’s a major limitation for some. The inputs are very limited. Either Ethernet or USB. Ethernet sounds the amazing. This is extremely well optimized. USB input on the other hand should at best be completely avoided unless there is no other option available. One workaround for those using USB input is to use this to add the music to internal drive and play, if possible. Music from internal drive sounds the best among all sources for obvious reasons. You also have the option of using AES, SPDIF or optical inputs. Only the user can determine if it works or not for their system. please note, these above statements only apply to inputs.
As far as outputs, the one that is clearly optimized for the very best sound is AES. It is limited to 196khz or DSD 64 but I don’t believe anyone can really differentiate this from even higher formats. USB output is good but not to the level of AES. There is no I2S.
After my home trial, I decided to purchase the Grimm MU1 as it fits my needs and my system. It provides such an upgrade to my system, it is a no brainer. I already asked my dealer to send me a new one and hopefully will get it next week. Appreciate all the input received!