I use dialog internet in my phone (galaxy s2)
Connectivity is changing from HSDPA to 3G to EDGE and even then to GPRS all the time regardless of the place.
Most of the time I use internet I had to use either GPRS or EDGE.
I have 1GB data package bought just for the stuffs in the phone (software update and light web browsing etc) but now I don't use the data package. I only use my phone to access internet when there's a wifi network available in that place.