Someday I won't buy DRM'd eBooks, but, not until books I actually care to read are available that way. To me it's more important to prop up an actual eBook industry before going all activist about DRM.
That said, I choose ADEPT ePub because the DRM stripping is both easy and results in an unaltered ePub which is my format of choice when not using DRM.
If you were to exclude that reasoning, then I'd choose eReader because I can read them with Stanza on my iPhone. If there is ever a reader worth using on iPhone that supported ADEPT ePub then I'd lean back that way. For now, txtr is the only one, and it's awful
inept epub for the win...