I have IDEA 3G plan of 300 MB. At first I used to switch data ON/OFF to save phone battery which would drain fast if I kept data ON with 3G whole day. But due to this my mails/weather/whatsapp etc won't sync automatically (obviously as data is off).
Then I started keeping data ON continuously, but kept mobile in 2G mode. So battery lasts whole day, and all apps mentioned above sync well with 2G. When I want to browse FB/Twitter or through browser, I change from 2G to 3G mode.
(Sometimes I forget to change from 2G to 3G, yet I am able to browser some webpages or apps like FB/Twitter, but images won't load as quick as on 3G 🙂)
So I can say IDEA 2G speed is also good. 😛layful: