I can still remember when the iPad first came out, I was certain that the WiFi one would be right for me. Well, that lasted about a week. Doing things on the iPad was so much better than the iPhone. Mostly it was because of the larger display. It's so much easier to use the touch applications with a larger display.
After 3 weeks I found myself wondering if I really needed my iPhone. I did some research and decided to try getting the 3G 16gb iPad and using either VOIP (which is now allowed over 3G) or a prepaid phone.
I tried the application from Toktumi, but the 2 second lag between response was just not ping to cut it. For my initial try I got an AT&T GoPhone. Depending on how the pricing is for Skype over 3G when they announce it I might try that. I also had been using text+ for my SMS, but every time I sent a message it was coming from a different number which just was not going to work.
For now I'm using a combination of the GoPhone and Google voice, and I'm really liking it.
I love the 3G iPad, it still has the same awesome battery life (it's almost 6 and it's still at 70%) and being able to use it anywhere is nice. I do want to find a good checkbook application, or I may go ahead and write one that suits what I want to do.
Next I'll be to cancel my iPhone and go totally with the iPad, GoPhone and Google voice.