These are my first impressions of the iPhone OS 3.0 versus Android 1.5.
I've been using Android for 3 months now and Android 1.5 for about 3 weeks.
I've only had 1 day with iPhone OS 3.0.
I'm running Android on a T-Mobile G1. I'm running iPhone OS on an iPod Touch 2G 8GB.
In comparison to iPhone hardware, I'm lacking the mobile network, the camera, and the built in microphone. Specwise, the Touch 2G is faster than the iPhone 2G and 3G but slower than the 3GS.
OnScreen Keyboard
iPhone
iPhone gets this right. The Android keyboard works, and even has some features that I prefer. For instance, when hitting "shift" the keys all change from upper to lowercase letters making it obvious if you are capitalizing or not. I also like that the word changes/choices appear above the keyboard (where my eyes are) and not up in the text (where my eyes only go sometimes). But, in the end, I can type A LOT faster on the iPhone keyboard and make fewer errors. And That's only after 1 day of use. I'm sure, in time, I'll get even better.
Physical Keyboard
Android
Since iPhone doesn't have one, Android wins. If you want physical keys, then this is a good thing. If you don't need them, then you don't care. As it stands now, I can type faster on my physical Android keyboard than I can on the iPhone OnScreen keyboard. As I get better at iPhone, that may change.
Browser
iPhone
The iPhone Browser is FAST and easy to use. It still stalls now and then, but not nearly as often as Android. Plus the multi-touch hardware really excels here. Android seems able to display everything it can and in every case I tested it does so just as well in the end. But it typically takes longer to get there.
Photos
iPhone
Android photo browser sucks. It's slow and complicated. Replacements available in the Market aren't much better. iPhone is fast and easy, as it should be.
Mail
iPhone
Despite the fact that the Mail app on Android is native to gMail and that I use gMail, I still find the experience better on iPhone. Deleting and sorting mail is fast and easy. Despite the fact that some things I use are harder to get to, the speed of the app makes up for any difficulty.
Push Mail
Android-ish
My mail doesn't seem to push at all on iPhone OS. But that may be because push only works with iPhone hardware and not with Touch hardware. Perhaps the mobile network is required for push? Regardless it doesn't work. And Android does. But only for gMail.
Push / Pull
Android-ish
Android doesn't implement Push. Individual apps do. Therefore, the apps must be running in the background to accept pushed content. When this happens, it typically works well, though each implementation is different. Other apps Pull content at regular intervals. This also works well but is more battery consuming, network consuming, and still requires the app to be running in the background.
iPhone has real Push. However, I've not seen many apps that use it. I tried AIM, because it was free and supported push. I found the Push interface to be obtrusive at best. I'm not sure if that method of operation is required or is simply how AIM chooses to implement it. Looking for other Push enabled apps to try.
I had hoped it would work similar to Android's notification bar. A pushed message causes something to happen. Usually, a notification of sorts in a common place to inform the user of pending interaction. However, ideally, it would also allow for an action to take place without user interaction. For instance, Loopt might push a request for location. I don't want to have to acknowledge that then fire up the app to update location. Ideally, the pushed notification would cause the update to happen and then the app to die. Apps requiring user interaction would notify in a common location and not with an annoying popup for each event. Then again, part of that may be AIM's implementation. Perhaps all that I desire is possible and AIM just used it poorly.
General Use
iPhone
iPhone is smooth. Everything works almost exactly as expected with only a few caveats. On Android, when scrolling around on a webpage, for instance, I often accidentally click links. This never happens on iPhone. The UI programmers have put a lot of thought into when users are scrolling and when they are clicking and how to tell the two apart.
The same is true for all of the menus. Everything is fast, and pops, and is consistent with very few exceptions.
3rd Party Apps
iPhone-ish
iPhone has been around longer. There are lots of good solid apps available for iPhone. Especially in the "games" arena. It's shocking, really. However, Android is catching up. And the Android apps that are available (General Use issues mentioned above aside) work just as good if not better (because of Push/Pull features) than the iPhone counterparts.
Hardware
iPhone
The iPod Touch screen is bigger and nicer looking. I don't have a camera to compare or anything like that since I'm working with the Touch. The Touch is lighter than the G1 and I believe the iPhone is as well. It also feels more solid in the hand.
Development
Android
The Android SDK is free and available on Mac, Linux, or Windows. The iPhone SDK requires a membership and is only available on Mac. iPhone apps can only be distributed through the App Store, The same memebership for the SDK is required. Prices run $99-$299 depending on use. Android apps can be distributed outside of the Market. Placing an app in the Market requires a $25 developers membership.