I have the 3GS and the iPad 1 wifi only. I always thought that the iPad was just a big iPod, until I got one. Even if they are both using the same technologies, they are different in their usage.
- it's easier to read on the iPad one because of the size of the screen. Emails, books, articles, etc...
- the keyboard is also bigger, making it a lot easier to write stuff then the iPhone
- battery time is around 10 hours of full usage... Can't say that for my iPhone...
- when doing remote over a PC, it's far more easier to control the PC on the iPad than the iPhone
- while traveling, by plane or train, the iPad is really good for watching movies. Your personal mobile theater
- it's lighter than a laptop, no booting time, no login in, can be used in landscape or portrait.
- it's more secure than a laptop, easier to use, no configuration to mess with...
The iPad is not an iPhone replacement, but almost a laptop replacement if you don't need specialized softwares or doing development. It's an appliance like the phone, the fridge or the tv. You use it for what it can do, and it can do a lot. I still like my iPhone, but now I use it more as... a phone. I like the fact that the iPhone can do the same thing as the iPad, but I still prefer the iPad for my virtual life.
Cons about the iPad...
- too big for taking pictures (iPad 2)
- too big for usage as an iPod or mp3 player
- still missing some apps found on the iPhone (but things are improving)
- exchanging media files, documents and so on with the iPhone is a bit messy without iTunes. Have to rely on third parties. But iOS 5 should solve that
- keyboard is bigger, but still missing some keys in the first panel like numbers, signs... Have to click the "123..." key to reach them
Those are not big issues, considering what it can do...
My 2 cents!
VicoPhone Addict!