I've used both Android and IOS. I first got the iPhone off a friend a month after it first came out for HK$1500 because he wanted to get the 8G (was it 8G? i got the 4G one). There wasn't Android back then and it was quite nice to use, after about a year or so I kinda got bored of it because at that time there wasn't a lot of software or tweaks you could do to it, so i wnt back to using Symbian on Nokia phones for the next 2 years. I didn't like the look of the 3G or 3GS so i skipped those.
After the iPhone 3Gs came out, there were Android devices available so I was thinking to myself what should I use? I was getting tired with Symbian, its just crap and the responsiveness of the Nokia touch screen is something you should just keep quiet about......
So i went ahead and got myself an HTC Desire HD. At that point i figured i would give Android a tryout since I've always used stuff by Google and they have served me well.
With Android there are lots of customizing you can do to the interface, the multiple homescreens are nice because you are put all sorts of funky widgets there, i liked this feature. At that time it was still relatively new and a lot of the software was still quite buggy. The camera on Android devices tended to be quite nice too. I also found the "buttons" on the homescreen to get home, settings etc were quite confusing, I've used it for the better part of one year and i still press the wrong button sometimes. The GPS was also a bitch to get a lock-on and reading online, this was something wrong with the Desire HD and there seems to be no fix for it. I wanted to get a phone with good GPS so i could use it when i was travelling so this defeated my purposes.
My girl got a cheap iphone 4 a couple months after release through a friend, so i set it up for her, JB, etc. Prior to this i've been using both Android and IOS for roughly a year or so, albeit at different times. At this time i found you could get app store apps via apptrackr/hackulous so that was great. I started to look for places where i could get apps from the marketplace so i didn't have to pay heaps of cash for GPS software, albeit my current phone needed at least 10-20 mins before i could get a lock on a satellite. Couldn't find any. This was my cue to get an iPhone again because i felt the iPhone 4's screen was much more responsive than the Desire HD i was using at the time and i made a point to test the GPS out and it works just fine on the iPhone.
In the end i got an iPhone 4, loaded it up with all the crap i could find. Works fine for my purposes. For me i liked the size and dimensions, it fits into your pockets just right. The Desire HD had a larger screen and the width made it a little noticable especially when you sat down.
Last month I got my hands on a HTC Incredible, i found out now you can find a site and app (but i forgot the name, you can Google it) that lets you install paid apps from the marketplace, but i was told by my friend that most of the cracked apps there are loaded with viruses and spyware. I would trust him because he is a convicted hacker (done time in the slammer) and he is now quite famous, he has been on CNN and other news publications/websites for hacking Android. He works for Samsung, but of course they will deny it. So I would trust him on this because I've known him before he got into trouble or even learnt how to hack and he has always been straight with me. He offered to crack any app that i needed for me so that i wouldn't have anything iffy on my phone, but i didn't need it since, the HTC Incredible was just passing through my hands at the time and i was just playing with it so see what kind of improvements have been made.
If you ask me, at the moment I would use the iPhone, as it serves my purposes, but there are pros and cons of using both types.
iPhone Pros:
1. Lots of software you can easily get for free with a JB
2. It looks nice and fits into your pockets easily.
3. Lots of tweaks, you can make it look and feel exactly like an Android phone if you want, hell you can even install Android onto it!
4. It depreciates slowly compared to many other electronics.
5. Its generally easy to use, esp for the less tech savvy.
iPhone Cons:
1. It looks like an iPhone, there is no other look, whether you like it or not you have no choice if you want to use IOS.
2. Itunes is a piece of shit.
3. The way they "shuffle" their songs is crap.
4. You need to JB to get all the cool features.
5. Need 3rd party apps to play movies in a format other than mp4/mov.
6. No reports of cracked software having spyware or viruses does not mean it does not exist. Albeit i read that some people have encountered this when getting stuff from the sinfuliphone repo.
Android Pros:
1. Lots of models to choose from. You can get one thats really expensive or you can have the same OS for a lot less money.
2. Its highly customizable without having to JB it.
3. You don't need iTunes
4. Plays most movie formats off the bat.
5. Memory expansion slot.
Android Cons:
1. Cracked software has is risks.
2. The interface can get confusing for the less tech savvy bunch.
3. The variety of models available make it confusing sometimes, so make sure you check all the specs and make sure you are getting one with everything you want before you take the plunge. The Desire HD had no front facing camera, and i needed it for video calls. When i looked at it, there was what seemed to be a front facing camera, and i thought such an expensive phone would not lack such a basic feature, well i was wrong......it was the LED or light sensor that looked like a camera.....
Its your choice to determine whats best for you. I use an iPhone, but i'm not a fanboy. I've used both Winbloze and OSX for extended periods and i'm never going to use OSX again. I'm considering getting the Galaxy Tab 7.7" unless I know for sure they are going to release an 8" iPad. I find anything larger than 8" is too big to be easily portable unless you like carry around a bag, which I don't .
Hope this helps........