Believe it or not, I'm actually on the 300MB plan. And yes, I still use my phone like any other human, answering emails, watching videos and browsing the web. I'm just surrounded by WiFi hotspots like crazy. After 15 days I've only used 24MBs and that's between two phones!
I used to be on the 1GB plan but dropped because I was barely hitting 100MB a month. And on the months when I needed an extra 300MB I could just go over. In fact, I could go over twice a month and on average I would still pay less per year. After all, I've only purposely gone over my limit like three times within the past year.
In some ways I still don't need the 2GB plan, however, I feel like I'm getting screwed if I purposely go over my limit now. 600MB vs 1GB was a negligible 400MB difference. I wasn't using it anyway. But 600MB vs 2GB is a pretty noticeable 1.4GB difference. That's a significant chunk of data that I'm losing out on. Even going over twice still leaves me 1.1GBs short. It seems like the logical thing to do is just sign up for the 2GB plan and not worry about it.
I would get a lot more data for only $20 more. Plus that's still $39 bucks cheaper than what I was paying for AT&T around this time last year. >.<