I pretty much agree with everything said here. My brother has the Pantech Duo and IMO it's made of very cheap plastic and the sliding is terrible (get's stuck, sometimes opens both ways at the same time, which isn't supposed to happen and confuses the phone)Your title sucks. But as far as your questions. I just upgraded my phone, I was looking at all of the ones you listed.
1)Pantech duo- felt like a flimsy piece of plastic in my hand. IMO junk. But it is just as small, if not smalle then the pearl, iirc.
2) The pearl- A few people I know have them and more than one of them has had their trackball break off. And one them had problems with it freezing.
3)The curve- Seemed like a solid phone. Good features, etc... This was the runner up
4) The blackjack 2- Tons of features, windows, gps, large memory, easy to use, etc. Went with this and it's been good to me.
Out of those I would go with the Blackjack 2 as well, but that's because I prefer the blackjack's windows mobile over the blackberry software. I've owned the blackjack 1 and the 2 is simply the same with many improvements. So go for the BJ2 IMO.
