Try it with analog before you condemn it. I'm 100% with you on it really irking the crap out of me when I first got my Ultra because while I'm not a professional musician I do work in professional studios for a living and I was right about where you are now...I'm sending it back.
Now?
I don't even bother messing with the digital stuff (or USB portion except for AxeEdit) with it and to be honest I don't miss the headaches with clocks, sample rates, bit depths, etc. If you've got a good interface (which you have a great one) the balanced analog outputs are extremely good and I believe you have MORE flexibility using them. I nean you know that if you are too hot at the source in digital it's just clipped and you can't adjust it without going into the thing to edit the patch, but with analog you just twist the front knob a touch and it's fine.
Just make sure that you get the levels set; your input levels should tickle the red when you bang on it hard (set in the first page of the I/O menu) and the output is usually run all the way up which is supposed to be unity gain for all intents and purposes.
I don't have AES at home right now, but I did do some A/B testing comparing SPDIF and the analog signal through my interface and I couldn't for the life of me find anything significantly different besides the fact that I can't control it if it clips. The D>A convertors in the AxeFXII are fantastic, let the audio interface do the work.
You got nothing to lose by trying it, right?