Alright, well maybe this will help.... and this is serious.
Both myself and my girlfriend had At&t Tilt cell phones (also known as kaiser, or tytnII). We loved them, and they were about 1 million times better than anything else At&t sold... including the original iphone (due to lack of 3g and gps). However, we were tired of having to install new roms and hacking the tilt to get it to due the things we wanted.
There came a point where we both wanted phones that were GOOD as an actual cell phone.... you know, for dialing numbers and handling the call. We also still wanted a phone that would allow us to play tons of games, and do that GREAT as well. We had to have GPS, and we really wanted 3g because we browse the web on our phones. Well, the iphone does every bit of all of that PERFECTLY. We also needed something that would handle our calendars / appointments and act as a PDA, something that could have custom ringtones and graphics, and had tons of memory (or the ability to upgrade it) so that we could play music on it (like an mp3 player)...and we wanted something light weight and thin.
The iphone had all of that, and did all of it well. That's why we upgraded. Trust me, do it... and don't look back. Don't jailbreak it, just use it as it is... you'll love it. Are there some quirks right now? Sure, just like with every phone out there.... but the real question is, "Is it still worth upgrading to the iphone 3g"? Yes, it is.... absolutely 100%.
Reasons to upgrade to the iPhone 3g:
- Browsing the internet, is really like browsing the web on an actual computer
- Email, works great on the iphone. Viewing it is excellent, and actually fun.
- BUILT IN 16GB (OR 8GB) HARD DRIVE!!!
- BUILT IN IPOD TOUCH / VIDEO
- Tons, and tons and tons of games. Oh, great graphics, like a PSP!
- Built in GPS, works great as well (regardless of what some people say)
- Alarm clock! Yes, it has an alarm clock & stop watch that work great. LOUD!
- It really does actually work good as a PDA. It'll read all your documents fine.
- APP STORE! There are tons of apps for about everything you can think of. Check out the app store online on APPLE.COM to see some of the thousands of apps. If you can think of it, you can just about get it on the iphone.
- Threaded SMS text messaging that works great
- Contact lists, with ability to assign ringtones and pictures
- You can re-arrange the home screen and icons
- SPEAKER PHONE! Loud and clear!
- Wifi, works great. It actually picks up access points my laptop doesnt.
- Bluetooth. Also works great.
- VIBRATE SWITCH.

You dont need to turn the phone on even, just flip it.
- Very clear, and vibrant screen with excellent colors.
- Cases, and screen protectors look better on the iphone than any toher phone i've ever had. Get an incase silicon black case for the iphone3g (not original iphone), and get an anti-glare screen protector (from the apple store), and you'll never be happier.
- Slide to unlock, is awesome. Search youtube.
- The camera (although on paper it looks small), actually takes FANTASTIC PICTURES. I had a 3 megapixel cam in my tilt, and the iphone takes better pictures. Go figure!
- You can still email pictures to your friends using ##########@mms.whatever.com
- Battery life is awesome. I got 7 hours of use and 22+ hours of standby, and still had 20% battery life left. Yes, im serious.
- Charing only takes about 90 minutes or so.
Those are some of the ones i can think of off of the top of my head... i'll add to it if i think of anymore. Honestly, this thing does everything.... there's absolutely no reason to have to "think about it" or "debate".
I was in your shoes, and avoided the iphone forever. I talked all kinds of crap about it, and said I would and could never go without a windows mobile phone. Yet, here I am today never looking backwards.
There are some bugs, but nothing major. EVERYTHING works great. Occasional short lived lag with the keyboard, occasional program closing (which doesnt freeze... it just closes).... but that's just about it. I can name a dozen other phones that you might be thinking of getting that have the same or similar issues.
EVERY phone you can think of has its own set of problems, but the iphone has less I can promise you. Some people complain and complain on here, but ya know what.... they havent done enough research or something. I'm a regular on a few other mobile phone sites and every other phone has issues as well... many of them are way more severe than these. Apple is also good about fixing the issues, and they come out with updates pretty regularly (VERY unlike other cell phone companies).
Remember..... Nike. Ignore the haters.
Who couldn't use a: 16gb portable hard drive, PDA, Mp3 player / Ipod Video, handheld gaming system, alarm clock, cell phone, and all in one gadget (again thanks to the app store)? =)
On paper, it may not look like much. Other cell phones look great on paper, such as the At&t Tilt... but it all comes down to how the phone operates and this thing is a king among a village of terds. Hope that helps, and I really do hope you get the phone.
OH, and At&t is a pretty good network. I like them, and they have good customer service for the most part (compared to Verizon and other companies).