In my experience, iOS just seems to work out of the box; the stock apps work well meaning to don't have to fuss about downloading and testing various apps until you find one you like or that works well
This is one of the key differences. With Android apps, not every app will work on every Android phone because there are so many variations, particularly regarding the processor and screen. You might have an app that works brilliantly on a Samsung Galaxy S2, but not well on smaller phone like my HTC Wildfire.
With iOS apps, there are only 5 models that they have to work with, although granted some of the new flashy apps don't work on the old iPhone 2G or 3G very well because the processor isn't upto it, but since you're looking at an upgrade, I would assume you'll be going for an iPhone4 or 4S so that's not a problem.
I've had a few niggles although I put that down to it being a works phone and being handed down. First one the mic packed in and my current one although people ring me, the phone itself doesn't ring sometimes meaning you have to switch it off and back on again
It seems that even Apple have the occasional problem with phones. Older used iPhones do eventually start to have problems, but so does everything.
But I've recently been hearing more about brand new phones failing. One of my colleagues has had her iPhone replaced 3 times because each one failed in a different way.
It is personal preference, Android versions can vary quite a bit between phones.
It also depends on whether you want to be tied to an expensive contract.
Is there anything wrong with your current phone?
If not you could just keep it for a while and have a cheap SIM only contract.
