What are you changing it to Chico? It's still Android, you're just running a customer ROM. You can change the skins and use custom ROMS on iPhones too. Personally I don't, it gets annoying when you keep having to tinker.
My mate's heavy into the Android stuff, he's for ever moaning about something going wrong with his custom ROM. It reminds me too much of the old days on Windows Mobile OS. These days I just want the easy route of being able to use the phone and go. iOS 7 will be unveiled in a couple of weeks, that should be interesting.
I've got a Nexus 4 in the house. It's still got the plastic on it, I was going to give it a whirl with Ubuntu, but it's just a developers window dressing of an OS at the moment. No real functionality, and the apps don't work.
It depends if you're into the customisation of your phone mate. Some are and some aren't, the ones that aren't use apple.
With the ROMs you can easily choose the stable version but nerd lids go for the beta so there will be issues. I never have an issue off JellyBam and can use it to under clock or over clock my phone for instance, so all aspects of the phone are up to you. I seldom go that deep into it but it's useful.
Can you do that with apple? lol.