Modi needs a power adaptor, but if you don't intend to use it on the move, then it's definitely good.
If you can hear the difference between DACs, you have keen ears. Seems like the majority of people can't... but
I'd better mention that I used Modi Multibit with Little Dot I+ and had earth loop noise problems. (High pitched buzzing when moving the mouse, etc.) I didn't have the same problem with a fiio E17. These problems effect everyone differently, though, and you can't blame any individual component.
As far as I know, only Schiit and Chord do significant independent DAC design. I got the Modi Multibit because I wanted to support that. I don't think I can hear any difference. I solved the noise problem by replacing the Little Dot with a Schiit amp... for the same reason again; no problem with the Little Dot. As @ItWasGreat said, no regrets... I think it'd be hard to find anyone that regretted buying a Modi unless they were really spending their rent money.
Nice! I have the Vali 2, listening to T50RP mkIII.
(I wish the HE400i wasn't tempting my curiosity right now, being half price on amazon. But the thought of finding out what the T-X0 sounds like is keeping other thoughts at bay till December.)