So I installed this new Echo Mia card and am of course having a really rough time with it. The ASIO drivers work more reliably for it than with the Darla24, but there's still a lot of erratic clicking and popping here and there. Using the virtual outputs to record from Reason to Sound Forge will cause a whole bunch of clicking and then usually it will crash the whole system.
The sound quality is a bit better than the Darla24, but I don't think it's $350 better. I was never that unhappy with the Darla's sound quality, just the stability when trying to push it to the limit with VSTis and also the lack of multi-channel support.
So unless something miraculous happens, I will probably be returning the Mia. I may try out a Delta 44 for the stupid hell of it. Failing that, I will quit music and become a clown.