I briefly owned an iMac (2011 version) but really didn't like using it at all. I found myself going back to my Windows desktop all the time and luckily the iMac was still in its return period so returned it back. I can't say anything about the Macbook (the laptop) since I've never owned one.
However, I love the iPad and everything about it. I can't believe the difference in user experience between an iPad and iMac, but then again, I've used a Windows system for years so maybe I couldn't get use to the iMac and isn't really all that bad.