Got the Discdream 2 a couple of days back and enjoying mostly with my BW P7s.
First of all it looks awesome and is quite light, however quite bulky so can't fit in any form of a pocket (the Fiio DM13 might just but I couldn't get past the generic design).
It sounds really well balanced, the bass is a bit subdued, but the vocals and treble shine. So far plays all my discs and doesnt skip when lugged around in a backpack. Simple clear buttons and battery life is fine.
Connected via Aux to my BW Zeplin Mini, it could use a bit more volume so have to crank the levels to the 60s/70s which is fine. Could use an amp in the mix in that scenario. For my type of easy of drive headphones/IEMs (tested the Dunu Alpha 3 as well), it's perfectly adequate.
I tested the USB DAC function and also works well, even with my android it was plug and play and could use with UAPP. Volume needs to be cranked higher in this scenario, and sound isn't as crisp as the CD mode. But a nice bonus if you are sitting in the office and want to use it as an all in one system throughout the day.
If this lasts a while as it hopefully should, it's a nice to have retro nod to the easy days! Had a lot of remarks from my younger colleagues at work who thought it looked very cool
Btw, I checked the specs compared to the Ultra, and it's the same CS43131 DAC and possibly same amp. Only difference is that the Ultra has two of them as it supports Balanced as well. The power supply circuit seems slightly better specs on the Ultra (7 vs 6 linearities) and that's it. What you gain with the DD2 is the lighter weight, funkier colours and the price. It's more my jam as I use it as a discman. For stationary CD playing, I have a TEAC transport hooked up to my soundbar via optical.