I moved from iOS to Graphene back in March, and have never had an issue with it, despite having to very suddenly learn how to Android.

It takes longer to figure out what apps and data you want to keep than the actual loading of the ROM onto the phone.

They're more reliable because you have a smaller set of things that can go wrong without all the bloatware. Now if you're doing crazy Android magic, then I understand what you're trying to say about the reliability part.