I looked long and hard at just about everything. Gathered all kind of specs etc. I narrowed it down to 001 and Delta 1010. Went with Delta because 001 has limited midi ability, lower specs(how much it means in the real world, I don't know), lower tracks, and you're basically limited to using their software, including plugins. BTW, it uses what Digi calls RTAS plugins, which are considerably lower price and quality than TDM, which it cannot use. TDM is arguably what makes Protools stand out from everything else.
On the plus side for 001 is that it comes with software. Technically, Delta does too, but it's even more limited than Digi 001's software, which I believe is called LT for light. You can take your projects to a pro studio and directly seamlessly(?) import it too their full blown Pro-Tools and use TDM etc. there. Also, 001 comes with 2(?) preamps, although often criticized. Delta has no preamps.
Digi 001 is probably easier to get setup and running, and more complete all in one package, and better than most people will ever notice. They have(used to have anyway) their own pretty complete forum also.
Delta 1010 is higher quality(possibly pro level sound), more expandable, more options, more powerful, but more thought is required to finish up the rest of your system. I have had excellent results the few times I've needed to call support.
If you're really into midi, it's a no-brainer: not 001.
