Just updated to iOS 4.0.1 on my unlocked to T-Mobile, jailbroken, and imported iPhone 3GS 32GB and all is mostly smooth thus far. Only took half an hour to complete backup and update plus download time. On the Clear 4G network it took me 15 minutes to download. Figured I would share what I have discovered thus far for anyone else that is consider trading jailbroken apps for the new iOS features.
First thing I noticed is my iPhone will not sync at this moment. Which may be due to the fact that I cut and pasted pictures out in a hurry the other day to make room on my phone. I did not have this issue before the update. As soon as I sort this out I will update this post.
The phone works fine and since it was imported it is still factory unlocked on the T-Mobile network. If you have an aftermarket unlock this may not apply, I have heard you could lose the unlock and may need to reapply it, please research that further for yourself. Funny thing is that I do suddenly have more bars, though I doubt better reception. Studies indicate any difference is marginal at best.
There is a remnant of the jailbreak buried in the slew of apps and I still have my background image. I also have a fast key button left over from an app that allows you to create them. Had two before and the only one still there was a bookmarked website. The other was a speed dial key to my girlfriend. Aside from that all jailbreak apps are of course gone. Sadly, this included some handy apps including iBlacklist which allowed call blocking.
The mail has changed and now offers an "all mail" option for multiple e-mail accounts. So awesome for those of us managing several e-mail accounts.They cleaned it up a little bit and it separated the Accounts(containing account folders) from the inbox. This way you can go directly to your inbox.
Surfing the internet I went to a flash site hoping to see it work and I was still disappointed. Not that I really expected it but the Droid X has Flash Player 10.1 so I would think iPhone should have this by now. Not sure yet when iPhone will have this capability but it has already been displayed at the Mobile World Congress(MCA). Hopeful though since instead of the little question mark box I see the loading status icon, so perhaps my connection is too slow.
How to use the option to create folders update is not immediately apparrent to me. Very simply, you drag one icon onto another and a folder is created. You can then name the folder. Very useful and it is about time they take care it.
The zoom feature also took me a second til I figured out you just tap the screen three times. It appears you can even select the area of the screen to zoom in on. Again, why this was not released earlier is beyond me. I do not believe I have ever owned a camera phone without a zoom option before the iPhone.
I will stop there and let you discover the rest of the features yourself. Good luck with your own upgrade if you have not yet updated. For those of you who have, please share your experience. For details on the features of iOS 4.0 on the 3GS just visit Apple.