A long time I was working with Delicious Library 1 & 2 and I was happy with all the given features. But with the time I wished me some other features like linking to Trailers on my HD or the web like over YouTube. I go sometimes in contact with the developer over mail or on their "complicated" feedback forum, but nothing has changed over the years. Also the application was slowing down with my growing collection (over 400 DVDs). The final brake with Delicious I made, as it was more and more clear that they won't develop again an application for iOS. Well, there was one in the past, but the dev. run in trouble with using the Amazon API and he dropped the mobile client.
Now I'm working with DVDPedia for around one year and it works so great for me. The beginning was a bit tricky, because I has problems to import my Library from Delicious Library 2, but after I contact the support over Mail, they helping me in less hours. So the support is gorgeous at ever point where you need help or has suggestions.
Also I can insert now a lot of more details around my movie collection as I ever can do before and I love the connection to a wide range of different sources to complete the movie informations... For example: If you fill in the IMDB ID of the movie, you can simply import all the information's of the selected movie in seconds. If you fill in the original title of the movie, you also can safe the time to fill in the IMDB ID, but for German movies this will often not work and I'm a German user.
Also I love to have some own free forms, where I can insert keywords who I prefer and the application will remember this keywords for future filling.
And the best thing is, that there is a mobile application available to, to sync my full collection with all the list's who I created.
This will safe me also sometimes a bit of money or time, because in the past who I using Delicious, I bought sometimes a movie two times in the store.
The only thing who can be a bit better is the handling here and there. For example... If you hit the shortcut "cmd + n" it will create a new folder. Personally I would prefer it will create a new entry for a new movie. But the command for this is "cmd + f". Well... F for found I think. But If I would found something, I prefer to using the search in my own lib and not for a new movie.
Also I missed sometimes a bit greater OS interface. Well.. It's a database, I know... But pls. let me dream a bit ;-)