I have used Airtel mobile office for myself,i must say my experience wasnt the best.but its not bad for the money we pay for it considering there isnt any download limits or anything.Regarding speed,during off peak hours ,u get decent speed of about 6KBps constantly.but during peak (read 5pm to 11pm) ,it goes down ,its pathetic 2-3KBps.With EDGE the situation is like 2.5-3 times better than gprs. Another problem with MO is all gprs users share same (external) ip(!) (Remember link-removed one ip limit,its basically a mess if u do that). p2p can be barely used,but there are workarounds,but dont expect much.For query's about mobile's and configuration u can ask to some mobile phone forums like esato.com or something.