[Samsung Galaxy Nexus] red 90:
Coming from a and Iphone 3g myself I can offer some opinions after going to the galaxy nexus:

Pros of the iOS and Iphone:

1. Battery life is better - with the GN I'm finding all sorts of ways to decrease my battery usage from different kernels, darker wall papers and apps, etc. I find it adequate now, but definitely not as good as my GF's Iphone 4s

2. Speaker much better - you'll need to get some apps to increase the volume on the GN, which intern distorts the sound a bit

3. iTunes (can be a pro and a con), everything is quite integrated with itunes, all your photos, videos, music, books etc... it's all one system and one place. Where as with android I find you have the flexiibility to choose whatever you want, but it's not as integrated. Even backing up the GN is not easy unless your rooted and have clockwork mod. if your a bit of a techie, it's not really an issue.

4. Specifically for the 4s, the Siri system works with bluetooth... for some reason, the google voice commands don't work with bluetooth. Just this stupid generic voice recognitiion that doesn't work very well.

5. Accessories - With apple, there is a whole slew of Apple and aftermarket accessories that work with the phone... Samsung can't even get their own accessories to launch in a timely fashion.

6. Apps - undisputely there are more apps for the iOS. Reality is that it's not as big of a detriment as Android has plenty of apps and most of the important ones.

7. Smoother scrolling - Android is not as smooth in the scrolling and will studder. It's not bad, but when you put it next to an iOS device you will notice it.

8. High Resolution Contact Pics - This is just something stupid on Googles part. If you load up High Res photos to your contacts and it's sync'd with your gmail, the high res photos will be downgraded into this pixelated mess.

Pros of the Samsung Galaxy Nexus over the iOS:

1. Big ass screen - this makes browsing, emails, pretty much anything more enjoyable. I find I use the GN more than the Iphone just because of this... probably also why I drain the battery faster too :)

2. Highly customizable - once you play with custom launchers, roms, kernels, you'll get the phone to exactly how you personally like it

3. UI controls - after you get through the learning curve, it's actually much faster accessing anything on the Android. Everything from quick menus, toggle switches.

4. Widgets - darn cool to have widgets and things that update automatically in the menu screen.

5. File System - you can actually see what you download, where things are stored, manipulate them like it's on a PC

6. Notification screen and icons - Much nicer than the iOS

7. Google Music - can load all your songs up there without having to pay!!

8. Navigation - Turn by turn navigation as well as seeing things on street view. much better than the iOS

Overall, I'd say if you like to play with your electronic devices and let the geek in you come out, the Android is a wonderful device that can be customize to your needs and wants. If all you do is take it out of the box and want it perform at it's best, the iOS does that much better. I find the iOS is a purposefully designed device and works as it should right out of the box. Whether the design suits your needs is another question.