I had my surgery on May 24th 2011 also!!! It sounds like we're on a similar track, I lost about 60 lbs (from my highest weight) at 6 months and I'm down 90 from my high weight and 77 since my first weigh in.
To the OP, try not to compare to others! You're expected to lose 1-2 lbs a week...so if you're losing about 6 lbs in between each fill, you're doing your job! If you're losing more than that, great! If you're working out and losing even more, AWESOME! You'll get what you put into your band...when I slack at the gym, I average a little over a pound of weight loss each week, when I hit the gym hard, I typically double that! Work hard and continue evaluating what you can do with this tool, it will only work as hard as we do!