Despite the modest turn out at Apple and AT&T stores for its release, looks like the iPhone 3GS is just as hot as last year's model, selling over one million units over the weekend.
I too picked one up and it didn't fail to impress. Speed has definitely been on tap as I instantly noticed that it loaded apps in seconds that typically took several seconds to load. The speed here seems a bit clichéd (especially if you've been reading other reviews saying the same) but is well worth the $100 difference between last year's 8GB model currently running only $99.
But what have I liked most? Web browsing. Surfing the web was cool at first with both the iPhone and iPod Touch, but when you got to chunky sites with huge discussion threads like Slashdot, things really got to be a pain when the Safari browser would slow to a crawl or outright crash. Doubling the memory and CPU clock speed definitely helps with this use case and it has not disappointed at all. Copy/paste make the experience even more manageable, especially when used to clear large amounts of text from a text area.
I used the iPhone all weekend and did not notice a single oily smudge on the device. Compared to a friend's previous generation phone, mine retained its nice clean mirror finish.
So, anything to dislike? I'm not sure if my device is messed up or there is a lot of interference, but the GPS is woefully inaccurate. I've attempted to get an accurate reading by disabling the 3G and WiFi connection on my iPhone, but I've had its reading put me as much as six miles away from my present location.
Video taking hasn't impressed me much, either, but I'll admit I haven't actually downloaded it onto a computer yet. The resulting video looks 'smudgy' and the audio didn't seem very loud on the iPhone itself, so I'll have to do more investigation on what it looks like from another computer.
All in all I'm very happy with the device and it was totally worth the wait.
UPDATE 16:18: I'm going to chalk up the GPS problems to interference at my house. I took the iPhone out for a spin and noticed near flawless tracking once I had left my home. Time to do some investigation...