My 8 year old son is now using the original iPad. My wife won't let go of her iPad 2...and I'm using the iPad 4. We've also got a 'family' mini...that my son and I use often. I run a mobile sound production company...and the business uses 4 iPad 3s. They've literally transformed the way I do business...from signing contracts and collecting money to back up audio control and front of house mixing (we bought into Mackie's new line of mixers).
4. It's a computer replacement for me. I don't require PC level power for my needs but I'm on the Internet a lot. The iPad and my iPhone 4S get the job done nicely.