So here's my current situation... I use a Mac laptop, iPad (2 actually), and iPhone. I also have several windows computers. The main thing I love about the iPhone\iPad\Mac is the ability to use iMessage anywhere. It's also a huge frustration when I have to use my Windows computer to not have the messaging available. Aside from that functionality, I would move to Android. Is there something similar with Android to iMessage that will work on every device (iPad and Windows too).
There's a few other things I would miss, because everyone in my house is on iOS, but I think I have found ways around some of those missing features, mostly by using Googles applications for the iPhone.