Nook Collections is a pain
Beginning of July, I bought the Nook touch and Kobo touch. On the Nook touch, adding collections was a pain because you can only do it from the device. (I don't know if there was a firmware release afterwards to make adding collections for the Nook easier.) If you don't have a lot of books, this might not be a problem for you. I had about 300 books and there was no way I was going to do my collections on the device itself. You had to scroll through the whole list of books, and select which book goes in the collection. Then go through the whole list of books again for each collection!
With the Kobo Touch, there is the shortlist, which I really liked - I just added the books I want to read to that list. And then the search functionality for the Kobo Touch was nice. If I typed the first letters of an author or title, Kobo Touch is already filtering the list for me. I decided I didn't really need collections after all. Nice to have for me, but not a deal breaker.
In the end, I returned my Nook and kept the Kobo Touch.