The only thing attracting me to KOReader for my PocketBook is OPDS. The few presentations I've seen show a UI so bloated (as in, the main view for reading pages crammed full of widgets on the bottom of the screen to display wifi signal, battery percentages, and progression counters) that it makes me wonder why some people use an ereader at all.
If my PocketBook had OPDS out of the box it would be the perfect device. What has your experience been? Why are you using KOReader?