Replying to Ticket, court or no?

Ok I was driving along and got pulled over for speeding, the cop said that I was going 82, and I was in a 55. Also my insurance card was old, and past the expiration date, however I did have insurance, I just had forgetten to switch the old card and the new one. She wrote the ticket and said I was going 79 instead of 82, so it would be a lesser charge/fine, and she didn't write anything about the insurance. The ticket was for $135. I can either pay the money or go into court and try to get it reduced or dropped. But she said if I went to court she would tell the judge I was going 82, and that I didn't have proof of insurance. The insurance thing isn't a big deal because I can prove that i had it. Can the cop even say I was going that fast if she didn't write the ticket for that speed? What should I do?