Depends on usage. One website noted with videos 250mb didn't last long. If only email and Internet, 250mb maybe enough. As other poster noted you get a warning and I believe can upgrade then. So no harm starting with cheaper plan. I did unlimited since I plan ton stream video.
I did the 250mb plan as I intend to use it mostly on wifi. In less than 24 hours of what I consider to be 'light' usage (before I got my new DSL router, iPad didn't like my old one), I used about 50mb. This will usually be satisfactory for me, as 3G will only be used occasionally-supplementally, but I don't think it will cut it for anyone who plans to use 3G much.
My understanding is that when you run out of your 250 mb, it doesn't give you the option to "upgrade" to the unlimited plan. You can choose another 250 mb for $15, OR you can start another 30-day plan unlimited.
So, if on May 1st you sign up for the 250 plan, and after 3 days you realize you're at 249, you can sign up for another 250 (for $15) OR you can pay $30 and get the next 30 days unlimited. So, you're not paying the incremental difference between plans .... you're starting a new plan. At least that's my understanding.
AT&T data speeds are so pathetic (~400kbps if you're lucky) you won't need "unlimited". Unless you have a LOT of patience, you'll never use 250MB. And with that speed you sure as heck won't be streaming video, which is normally the only thing that'd crank you over 250MB on an iPad.
I signed up for the 250 mb plan on 4/30 and thought that would be enough. Just checked my usage and so far I have used 90 mb. I would have considered myself a light 3g user but it is looking like I will be buying the unlimited plan before my 30 days are up.
Donna
Just tested at 2.01 Mbps on 3G, obviously speeds will vary depending on location and local usage.
I did the unlimited for the first month, while I (so far) carry the iPad with me everywhere, and I may careful attention to a few things.
1. Even though I have unlimited, I turn 3G off and run only on Wi-Fi, even away from the house and work. That way...
2. If I really want on the internet, I have to make a real conscience decision, if I want to be on it just to be on it, or if I really need that connection without Wi-Fi present.
I have not noticed a way, with the unlimited plan, to see my data usage. So with my first month of testing, it makes things really hard if next time I know I can slide by with the 250 MB plan or I should go with the unlimited instead. Unless, there is some delay in showing the usage? Can 250 MB users see their usage immediately? I tried logging into and creating a login at AT&Ts wireless page, no go.
I just verified. With the Unlimited plan, you can't check to see how much you are using. I logged into the "Cellular Data Account" again, and for my status I simply have:
26 days remaining
Click on Full Account Overview, and it simply says Unlimited with start and end dates. Not too helpful, hopefully they can update this later on.