Best cheap, portable USB Guitar interface?

[brain21]

I'm looking for the best sound quality USB guitar interface I can find for under $175.

So far the leading contender is the Centrance AxePort Pro.

I see that the Lexicon Alpha is pretty cheap. How is the quality on that? The new Native Instruments mobile recording interface? I know everyone likes the M-Audio stuff, and I've got some of their gear (never liked their internal mixer application - it never works like you think it will). I know that the little $60 USB Guitar thing is not so great from what I've heard, but what about the rest of their sub $175 gear? Does it hold up to their higher-end stuff? Anyone been able to compare that audio quality with that of the Centrance AxePort?

I'm open to anything, but please, I would like recommendations based upon some sort of comparison. If you just happen to love the one you have, thats great for you, but doesn't help me much. :-) If someone thinks that the NI Mobile USB guitar interface is great, fine, but that doesn't tell me how it stacks up against the Centrance AxePro or the Lexicon, or some M-Audio or other such interface.

Thanks for any help!

Brain21