Having owned both iOS and Android phones, and currently using a 4S, I think the iphones are still the better devices. I hated how splintered the Android app market is and how annoying it was to try and figure out if your device was supported properly as some apps required certain level of hardware, or designed for a certain resolution. The big names are generally very good about this but it's not always there. I also don't like how many different app stores exist on Android, makes it a nightmare to track down certain apps that were once listed on one and now on another.
My biggest fear with Android right now is security though. So many
reports talking about Android being the biggest target, the least secure, or at least the most likely to impact the average user. It's scary to think that Google's lax policy could put your personal data, as well as your company's data, at risk just because they would rather have the stance as a more "free market" than what Apple offers. Perhaps Apple is too strict, but Google may also be too open in my opinion.
Android is getting better with each release, but you're still pretty much at the mercy of the carrier or handset maker as to when or if you'll ever see a version of android beyond what it ships with. I don't like that approach, especially because I still find some droid devices to feel so sluggish and that is often addressed with the newer releases being able to better utilize gpu accelerated menus and what not. Sure you can root it and run custom images but again, your work might not like that especially if you have to run any specific software assigned by them for what ever reason.
In terms of battery life, the iPhone 4 and 4S still rank among
the best on the market. Some metrics trade blows but for web browsing as an example, the 4/4S has a steady 3 hour+ lead over its nearest competitor. 3G talk time there are several Android phones that get better life, and if one of the ones offered to you is among them then I'd weigh how important that is to your usage. The battery bug on the 4S is somewhat strange because I own 2x 4S iPhones and while my white one gets exceptionally good battery life - just as good as my iphone 4 did, the black one I originally purchased (now used by my mom) is effected by the bug even with the 5.0.1 update. It means she has the charge the phone every day and it is quite bothersome. So heres hoping for a fix, luckily as a dev I can get easy access to the beta updates and will hopefully get a fix soon for her. Also...anyone who says you can't remove the battery on an iphone is just...well...flat out wrong.
Removing and replacing the Iphone 4/4S battery is as simple as can be. You remove 2x Pentalobe (3.6mm) screws that are down at the dock connector, push the rear panel up (towards the top), and the panel slides and pops out of place. From there you remove 2x small screws that hold the battery connector to the logic board, pop the contact off the terminal, then pop out the battery. Sure it takes a few minutes, but its hardly a nightmare...especially to anyone who has ever done something as complicated as...oh i dont know...building a pc?
Easy as Apple-Pie with the ifixit guides. Replacement battery is only
$30 if not less. So really, it's an extra few minutes compared to popping off a plastic panel and yanking out the battery. The tools are easy to find and usually come with the battery as a kit anyway.
Android still gives you lots of non-rooted configuration options as pantherx12 points out, but frankly I only see that as needed because google refuses to put any real polish on their devices. Maybe their solution of "let someone else fix it" works for people willing to do the research and test a hundred different keyboards and colors and what not, but for me...I like the Apple keyboard as it is and don't care to replace it. Looks great, works great, nuff said in my book. But you don't get the option of using Swype or any of those other neat new methods, which is a real shame.
I still vote Apple, but since I have a backlog of iOS apps from my previous iphones and ipads it's easy for me to see the value in sticking with Apple.
