Much has already been written about the Schiit Gungnir Multibit (Gumby), so I'm not going to reinvent the wheel here. Rather, I'll briefly discuss my interpretations on various questions, opinions, and disputes that are central to people's decisions regarding buying this DAC.
My evaluation system
Source: iPod Classic ---> Apple lossless ---> Pure i20 dock ---> optical ---> Gumby ---> XLR ---> Teac HA-501 ---> Audeze LCD-2F
When evaluating DACs, it's important to use the correct resolution of expectations. DACs won't have drastically different sounds like headphones do, but there are differences. When speaking of differences, you have to remember they are subtle differences, but the vocabulary used to describe these differences is more drastic than the actual sonic differences. Keep in that in mind. YMMV.
1. The multibit / megaburrito filter is not overhyped. Yes, this is a real thing. I'm amazed at how much information is on Redbook lossless rips. Lesser converters seem to throw it away or resolve it much less because I'm hearing sounds in my tracks that I've never heard before. I can hear the singers take breaths. Fingers on strings. It's not just the amount of information this DAC retrieves that is striking, it's what it does with it when it renders it. The spatial cues are amazing. Forget the 1st or 10th row analogy. I'm on stage with the performers. I can now hear sounds behind my head, which has never happened before. Previously, sounds were in front, above, and to the sides. Now, there is a sphere of sound.
The Gumby has completely eliminated any desire to explore 24 bit files or DSD. I'm perfectly happy with Redbook. There's a ton of information in those tracks.
2. The warmup period is real, but overblown. Yes, the Gumby sounds better when fully warm. But, it sounds great immediately after a cold start. It sounds better after an hour. It really comes into its own at 6 hours. 12 hours is where it maxes out. I noticed no improvements after 12 hours. I could easily live with this DAC by turning it on and listening to it after one hour. The differences between one hour and 6 hours is real, but not enough to make me wait 6 or 12 hours to listen. I live in an area with frequent thunderstorms, so leaving the Gumby on 24/7 isn't ideal for me. I'll leave it on when I can, but won't enjoy it any less if I am forced to turn it off and deal with a cold start.
3. The unbalanced outputs are not crippled at all. Several are reporting the Gumby's unbalanced outputs "clearly" lack behind the balanced ones. This is false. My Teac HA-501 is a single-ended amp, but can accept both unbalanced and balanced connections. I tried them both when using the Gumby. So, I had either the Gumby or the Teac do the summing. I could tell no difference between the connection type, and assuming my Teac isn't a piece of junk (it's not, it's a fabulous amp), it's because there isn't a difference at the human hearing level. Obviously, use balanced if you have an amp that receives them. Otherwise, use unbalanced without any fears at all.
I didn't pause the music and crank the volume to maximum to listen for any noise or hiss. That's a fruitless endeavor because it's way past listening volumes. I won't do this test, either. At listening volumes, and even above where it starts to hurt, I could hear no difference between connection types.
4. Cosmetic flaws do exist. This has basically been a dead horse around here. Yes, there are some slight cosmetic flaws on Schiit gear. Over the years, I've had five pieces of Schiit in my possession, and they all had very slight flaws on the metal edges from the cutting process or from little dings during the hand assembly process. Yours will be no different. Schiit keeps their money in the innards. If you want a fancy case, Esoteric will gladly take your $20,000.
5. It is vinyl sounding. I've heard others describe this DAC as the closest to vinyl as digital can be. I agree with this. Cymbals sound right and there's no digital glare. It's a very smooth and detailed DAC. Other DACs I've used in the past are either smooth or detailed, never both at the same time. The Gumby pulls off both, like a good vinyl setup can sometimes accomplish.
6. USB gen 2 is very good. Many people are wishing for USB gen 3 to come to the Gumby. I tried all the connection types I could--USB, optical, and coaxial. I could hear no difference between any of them. Also, my USB worked flawlessly using the same drivers I had installed for my Uberfrost. No dropouts, pops, noise, etc. It was fine.
Conclusions
This is an outstanding DAC. It exceeds every DAC I have previously heard. It is replacing my Uberfrost, and the differences are real. It is expensive, and cost more than 2x what my Uberfrost previously did. Is it 2x better than the Uberfrost? No, but it's extremely good and worth the price. It's less shouty than the Uberfrost, more smooth, more musical, more detailed, and more resolving--in relative terms that is.