The tl;dr version is best summed up from this comic
Now here are my thoughts.
Touch - iOS feels just like liquid under your fingers. I can't describe it but both the accuracy of the touch and scrolling is just better for me. Winner: iOS
Widgets- I loved this about Android, there were widgets for everything but most importantly I used a widget called Pure Calendar that would show me an agenda view in 3 lines for upcoming days. iOS 5 does a little better with notifications than it used to but nothing beats a widget for this. Winner: android
Notifications: The new iOS notifications are almost exactly stolen from android however they have improved upon them. Now I can see things like sender, subject, and what the notification is about. Android had something called "ongoing" notifications for things like music that was running currently that I liked but the amount of info available in iOS notifications is just better now. Another thing that android accels is infinite configuring of notifications, make the light blink, vibrate, don't notify all app configurable infinite ways it seems. Winner: iOS
Camera: It's impossible to know how every camera performs but the 4s 8megapixel takes much better pics than my EVO and the gallery is much faster and easier to navigate than the EVO andriod Winner: iOS
Google integration: This might seem like a loaded, item but if you depend on google services like gmail, google voice and google suggest, it's just better on android as you'd expect Winner: Android
Physical aspects: Android comes in about every size you can imagine. Big screens are a plus for me. It's the hardest thing about going back to an iPhone for me. I miss a 4.3" screen. You can have a physical keyboard if you want. Some of the phones are heavier and some are lighter than the iphone. All that said there's something that just feels "right" about the iphone. It's got a great build quality, the glass and metal make it very nice to hold in your hand. TIE
Apps: The apple app store is just better, there's better apps and the apps have more polish. I don't know if android is just more difficult because it's so flexible, the amazon app store is better than the native android marketplace, but without question, the experience, the apps and all things third party are better in apple's app store. The only plus to andriod is I can install whatever I want where apple has a tight control on their apps so you as a user can only install what apple has approved. Winner: iOS
Multitasking: Android by a landslide. iOS has some fast app switching things but with android I can leave one task to run or download, switch to another and know it's going to finish. Switching is better on Android too, just hold down the home button and your last 8 apps show up to switch too. Winner android
Battery: Unknown but with Android it varied A LOT day to day, and varies a lot person to person, device to device. I'll know more in a few days but Android probably gets a nod here to having a replaceable battery in most units. My experience with the EVO was really bad though in the until the last format. Edge: android
Sceenshots: I have no idea why google hasn't added this and it frustrated me at least once I week that I couldn't do it without rooting the phone. Winner iOS
Reliability: FOR ME, iOS is just better, I hardly ever have to reboot. There were times I was rebooting at least once a day on android. I formated my phone 3 times in the 15 months I had it due to lockups, battery issues, etc. The one thing (first world problem) that drove me crazy was bluetooth. I have bluetooth in my car and if I was connected to wifi and left my garage the bluetooth would disconnect. I also couldn't use my address book in my car, it was a small thing but was a big pain almost every day. Apple has a small number of devices and controls what can run and when on the device so it makes sense it would provide a little more reliability: Winner iOS
Storage: Well the great thing about android phone is that most of the time you can buy a cheap SD card to expand your storage vs paying outrageous prices for apple's memory. The downside is you have to manage what's installed on your SD card. Apps can be installed on your SD card but many times I got a low disk space warning because I only had 512mb on the phone and many apps have to run in phone storage. So managing the disk space was annoying. With iOS I don't have to manage it. I have 16GB to use anyway I want. TIE
Downloads: Better on andriod in every way. I never had to worry if I was connected to wifi to do something like with iOS. Download whole system updates over 3G, podcasts, audio books, ANYTHING. I hate getting the message in iOS this is too big for cell data. Winner: android
Sharing: iOS touted with version 5 they had deep twitter integration. That doesn't even compare to android's share button. With android any app could tapp into the share function, email, evernote, facebook, twitter, g+ and every obscure social site you can think of. All sharable from almost anywhere. Winner Android
Cloud: iOS brought us iCloud. It can store backups of my phone, apps, calendar, documents, photos and just about anything. After formatting my Android phone 3 times, I can't tell you how frustrating it was to have to reload most everything and the marketplace only seemed to keep track of my purchased apps not my free ones. It just wasn't seemless and you'd think that it would be. However google based things worked pretty well, contacts, calendar, email. Also the auto upload of pictures to G+ was a great cloud feature Winner: iOS
Voice: Android has had voice actions for a long time. Given I have a long commute I would use it a lot. I was amazed how good it was the first time I used it. You could give it simple commands like "send text to" "search for" and of course speech to text. Siri is just better though. I can ask it questions and it will talk back to me. Add to that iOS's new location based reminders and it's a pretty powerful combo. I think it still has a ways to go since I have to think about what I can ask it but, the fact it reads things back to me and has more action items than google voice puts it in the lead for me Winner: iOS
It looks like the score on these things is 8 vs 6 which is why I have such a hard time picking a platform. My wife might take this phone from me in March and give me a chance to reconsider platforms as google releases their answers to iOS 5 and the 4s.