I know a lot of you out there use Custom firmware, and there are a lot of great reasons to go with it. I am sure I don't have to tell you them. The number of apps are amazing, you can find literally anything, and I do mean anything.
Then there is boring old Official Firmware I can tell you there is at least 1 good reason to have a PSP with official firmware and that is the DLC. Because DLC will not run on custom firmware.
Then that leaves why go with DLC, a couple of reasons I will go in to details later and there is some really great as well really useless DLC. The best I found so far is Little Big Planet, it seems the game has bug where it can't be finished. There is a 34 MB patch that fixes it. As well as stickers and other fun stuff for free. There is pay mini game with a forklift that looks stupid. Then there is the Buzz Lightyear levels in Toy Story 3. If your any fan of the film, you will love these levels. Wipeout Pure, although not on Sony's site has dozens of extra tracks. Hot Pixel has more than 700 mini games. I can go on and on.
Me I have one PSP that is official and I get to enjoy all that stuff