I've used an iPhone 3G and 4 for the past 4 years. Recently I switched to a Galaxy Note 2 running Jelly Bean. My wife has an iPhone 5 so I use it regularly when her phone is close by.
For 75-80% of what most people use a smartphone for both Android and iOS are going to be very similar. Anybody that is familiar with one OS and goes to the other and makes a true effort to use the phone will have figured out how they work very quickly. 95% of the major apps are available on both platforms. Both iOS 6 on an iPhone 5 and Jelly Bean on newer Android phones are lightning fast to respond. I haven't noticed any lag on my GN2 (nor on my wife's iPhone 5). While I'll agree with the previous poster that I miss not having a volume mute switch like I did on the iPhone, I love having a Menu and Go Back capacitive buttons.
Trying to break it down I'd recommend if you want a larger screen or like the idea of Widgets on your phone, go with Android. If you like being able to sync your music and photos simply with iTunes/iPhoto or aren't interested in spending a little time learning a new platform, stick with iOS.
I'm loving my GN2 but a very big part of it is enjoying something new and different (and the screen size). My wife switched from an EvoShift running Gingerbread to the iPhone 5 and thinks it is the greatest thing ever. Neither iOS nor Android today "suck". They both allow some incredible things to be done from our phones that we have on us at all times.
One final comment about Android. If you've used or spoken with other people who have used older versions of Android (mainly Gingerbread), don't base your decision on that. It would be like talking about the screen of an iPhone and letting somebody tell you that they used the iPhone 3G and didn't really like it much. You need to compare current technology. iPhone screens today are about Retina display and Android today is about ICS/Jelly Bean.
Good luck with your decision and I'm sure you'll be happy with whatever phone you chose.