1) The Android system is a bit clunkier that iOS, but not much. It just needs some getting used to. Some of the slick features of the iOS are missing from Android; things you don't miss until they don't work the same.
2) That said, the hardware is a lot better. I added a 64 GB misco SD card for a fraction of the cost of upgrading an iPhone to the equivalent amount of memory. I can easily buy a 2nd battery and swap it in and out if I start using the phone so much that I run the battery down. I haven't even begun to mess with the NFC capability, but there is a lot of potential there.
3) All-in-all the move has not been that dramatic. Most of the apps I used on my iPhone are available in Android versions and work exactly the same.
4) Surprizingly, the systems sounds are the hardest thing to get used to. The defaults for the iPhone are burned into my brain, I guess. I can't find equivalent sounds for the Android, so often a text message arriving does not register as such until a few seconds after the fact.
5) I can't find any outdoor GPS software that is as slick as Motion-X GPS which I paid for and used extensively on my iPhone. I ended up buying BackCountry Navigator Pro, which does most of the same stuff, but is a bit less user friendly.
Right now, I guess the move is mostly a wash. The benefits and costs of the switch roughly cancelling. The fact that the Android was significantly less expensive than a new iPhone was and still is the tipping point.
Nifty CaseMate cover for my Android
Waterproof DryCase pouch for the phone