Disclaimer: I've never developed for iOS or Android. Honestly I think Developing for BlackBerry is actually pretty good. The other commenter makes good points

Disclaimer: I've never developed for iOS or Android. Honestly I think Developing for BlackBerry is actually pretty good. The other commenter makes good points about the vendor portal and responding to users, but the actual tools for development are great. There are so many options on what programming language to use, and the API documentation is pretty good. I don't know what it was like pre BB10, but I'm pretty sure it is a lot better now. They still have things to work on but I wouldn't say it is inferior to iOS/Android.