All the talk over the last week on the Internets has been focusing on the new iPhone 4 or the fully-enabled iOS 4 on an iPhone 3GS, but not everyone is getting a brand new iPhone 4 or already has a 3GS. This review is for those of you, like myself, who are still saddled with the aging (yet still pretty awesome) iPhone 3G. The following review will let you know what you’ll get in the new OS, what you’ll be missing, and will hopefully help you decide if it is worth upgrading.

The Good
The very first thing I played around with when it was done updating was folders. If, like many users, you have compiled 3+ pages of apps that you use frequently enough that you are unwilling to uninstall them and clean things up, then you are probably sick to death of attempting to organize your apps. Folders are like a dream come true. Although I cannot explain why it took Apple this long to integrate a feature that dates back to the original computer operating system GUIs, this is a feature that is truly welcome. Instead of 4 pages of apps that are loosely organized and a pain to navigate through and reorganize, I have managed to condense everything in to a single page with 4 main folders.

Once I was able to move beyond the excitement of having folders (Sad, right?), I popped open the mail app. The new inbox structure is great and navigating through the app just to get to each account’s inbox has never been easier. I’ve never really been a fan of a unified inbox, but from what I understand it is hugely popular and was a very highly requested feature, so kudos to Apple for adding it in. Also, for you business users out there, you can now access more than a single exchange account, so there’s that.

For those of you that do a lot of mobile web browsing, you’ll also notice that not only is Safari faster to load initially, but there are some nice new changes. For starters, you now have a choice of the default search engine and can switch between Google, Bing, and Yahoo. Along with the option of which search provider you want to use, search recommendations have been added and are powered by whichever search engine you select as your default. Supposedly there’s also better better HTML5 support and HTML compliance is extremely high, as my phone scored a 94/100 on the Acid3 Test (Note: Firefox 3.6.4 on Mac OS X 10.6.4 only scores a 93).

Are there more things that are awesome about upgrading to iOS 4? You bet, but those are the three that really stand out.

The Bad
The bad points about upgrading your iPhone 3G to iOS 4 aren’t so much as what’s wrong with it once you’re done but what you know for a fact you’re missing and won’t ever get until you buy new hardware. Most notably, multitasking, facetime, and desktop wallpapers. I understand that do to hardware liabilities multitasking and desktop wallpapers had to be disable or they would have just about crippled the phone (at least according to Apple) and facetime simply won’t work without the front-facing camera, but it still hurts to know the awesomeness that others are experiencing which your phone shall never enjoy.

The Ugly
Speed. Sure, a few of the built-in Apps such as Safari and Mail are snappier than ever, but I’ve started noticing more and more that it just seems a bit more sluggish than it ever used to. It is by no means unusable, or even anywhere close to it, but Apple has clearly switch gears to optimizing the software for the newest hardware. Even uglier is the crashing. This really can’t be blamed on Apple because it is an issue exclusively with 3rd party apps, so my guess would be this will be less and less of a concern as the app developers update their code for improved compatibility with iOS 4.

Conclusion
Overall, it is a very solid upgrade for the iPhone 3G. The addition of folders and the improvements made in Safari and Mail are enough to make the upgrade more than worthwhile. If, however, you’re concerned about some of the issues I’ve discussed above, then maybe put it off for a month or two until Apple has released the first bug fix (presumably to be called iOS 4.0.1) and more developers have had a chance to ensure that their Apps are up to date and working properly.