Right now, it's essentially a choice between iOS and Android. No serious third platform (Windows Phone, Tizen, BBX, third-party Android ROMs like Cyanogen, etc.)
Apple is decent (but not great) user experience, but has a few serious flaws: Apple's morality policing (and other restrictions) keeping apps users do want off the platform, as well as restricting people to using Apple cloud services for a lot of functionality, and not allowing some core OS functionality to be overridden. Apple's cloud services would be less of a problem if they didn't suck.
Android (well, the two versions; Google vs. the open version) have much more flexibility, but kind of suck. (way better than they used to be, but still inferior to iOS on a strict functionality basis).
I think it's inevitable that more and more computing moves to mobile (the next 2b people on the Internet may ONLY use mobile). Maybe Apple's cloud and policies will improve. Maybe Android will improve in quality. Maybe a new platform will emerge.
"Locked down" is awesome IFF it is locked down to the owner; if the owner has to do some small amount of work to lock down a different config, that's ideal. The "owner" might be an individual for a personal phone, or a corporation for a fleet of phones.