Dear Aunt TUAW: Which 3G plan should I opt for?

I'm planning on using apps like Trapster and Maps while driving with my iPad and knowing that with hardly using my 3G data on my iPhone as of late I still hit well over 300mbs in a month. When it was jailbroken and I could download podcasts over 10mb (at the time it was the limit) I was hitting 2GB. So I know I'm going all in with the unlimited plan.

Got my data plan on Friday at noon. By Sunday night I checked and had used over 280mb. I have done some face booking, email setup and some app installing from the AppStore. May a YouTube session or 2but stopped because the downgraded quality sucked so bad. I couldn't believe it and cleared the totals and did a test. I load Facebook via safari 4times and the total was 1mb already. Accordingly 250 is a joke and won't last more than a few days with light browsing.

"You must explicitly opt in for more data when your 250MB runs out."

this is incorrect. if you don't explicitly cancel your 3G iPad plan or opt out of auto renew, both the 250MB and unlimited plans are set to auto renew.

For what it's worth I have the 3G and on Friday I took my wife to pick up her car at the dealership and I took my iPad with we. I surfed the web for about 7 minutes and used 6.1 MB. I couldn't believe I consumed that much data in 7 minutes. I didn't do anything except log on to the NY Times to read a couple of articles and to check the golf scores at the Quail Hollow Championship. I signed up for the 250 but that may change pretty quick.

I would recommend the unlimited plan but I do agree that data consumption is a personal thing. To give you a rough idea I used approximate 60-65 mb (an educated guesstimate after checking the usage counter) for streaming 30 min of video using the netflix app.
So if your usage is even watching videos occasionally especially on netflix without wifi the unlimited plan is the way to go.
P.S I have the unlimited plan...

Probably a dumb question but if I don't use the full 250 mb in one month do I lose it? Can I mlk that 250 for longer than a month? I am in wifi 95% of the time so I won't use 3G that often.

If I use the data plan for a few days (e.g., while travelling) then cancel, is the charge prorated? Or is it billed for the whole 30 days?

Just a small point. The article says that "the experiment will cost you $15" but that's not quite true. If your usage is way over 250 MB/month then the extra cost might be close to this but in many circumstances it won't. Let's say that you really average about double the 250 MB/month rate. So in 15 day's you'll burn trough the 250 and sign up for the unlimited plan. That will run for 30 days **from that point** so after 45 days you'll have paid $45 -- just the same daily rate as if you'd signed up for unlimited in the first place. If you average, say, 300 MB/month you'll get 55 days "unlimited" service for $45!

In fact, if you use less than 500 MB/month, you might be better to stay on the 250 plan but sign up for another 250 when you're getting short. It will automatically renew when you use up the first 250 so you'l pay $15 more frequently but it will still cost you less than $30 per month.

I used the entire 250mb in 8 hours of normal to me use. Upgraded to the unlimited.

Tip: 15 days of the 250 MB plan is the break even point. I'l explain. If you make it past 15 days with the 250 MB plan, you can renew another 250 at $15 for another 30 days and over a year you will spend less than getting the $30 plan. It's worth trying, you're only gambling $15 to start.