I never caught the LIS movie but I was a big fan of the series. I agree that the earlier episodes were better. I'm not sure why I passed on the movie but I think at the time my feeling was that I really liked the series and I felt that the movie was going to try to make it something that the series was not meant to be. Wait, that sounds familiar....
"Stop it? I'm counting on it."
"But not because you threaten me. I'll pay you because... it's my pleasure."