I did my B Tech in the year 2005. I had a similar dilemma whether to go for an MBA right then or after some years of experince.
After around 1 years of experience i feel that gaining work experience is more important. It opens a new perspective of life, the new way of thinking . It imbibes a new atitute in you and that is more important when you will do a professional course like an MBA. You would definately appreciate the thing that are taught there more.
