Pros: right price - while still customizable
Cons: not portable
I bought my Maverick TubeMagic D1 about 8 months ago and use it everyday at work. Its on about 6 hours a day and I have had zero issues with it. Its a very well built unit and sounds great when paired with my ATM50's and Foobar on my PC.
I had the factory upgrade the OpAmps with OP A627's for 30 bucks and the sound is very warm and pleasing for good old rock and roll, hip hop, and dubstep. I use the USB digital input jack for the signal from the PC which was super easy because it just worked, no special drivers or anything needed.
For office use I love this little unit, its only draw back would be that its not portable as it need's 120v. But its not heavy or big by any means. When I leave work everyday I just unplug it and put it in my desk drawer for safe keeping.
This is my first headphone dac/amp that I have owned so I dont have anything to compare it against other than the standard output from my PC or smartphone which just sucks compared to the D1 output. Its an awesome upgrade for 200.00 bucks USD delivered IMO.