VODAFONE person came to my place and gave demo on 2g/3G after that I purchased VODAFONE USB in Feb 2011. and they provided 3G connection enabled internet free for one month f(Till 10th April)to all user after that the connection is switched to 2g which is very very worst.and almost all time not able to connect even 2G, i call "N" no of times to vodafone technical help but they failed to support.
For your information vodafone directly not hiring any technical person to trouble shoot any kind of 2g/3g issues directly, if u call for technical assistant for 2g/3G it will direct u r call to vodafone agents and they will be charged for every call(to the agents), so they wont provide you proper assistance.
So my suggestion is Never Ever go for Vodafone 2g/3G connection.