I started the "classic" version in February of this year, and within about three months lost 13 pounds (155 to 142). I didn't lose weight instantly, but boy did my shape change very fast.
It was hard as HELL for me though. I literally felt physically ill for the first 3 weeks. And if I didn't eat properly, I felt even worse.
My sister got married in early June, and once that "motivation" passed its been very, very hard for me to get myself "up" to do it again on any meaningful level. That's my biggest "con" about P90X - it is intense, and it takes alot of time, especially if you do it the way it is designed (including Ab Ripper X). It almost "scared" me off working out much at all, and consequently my weight is back up 8-9 lbs.
Therefore, I just started Jillian Michael's "30 Day Shred" - based on some recommendations from moms here. It is tougher than I thought it would be, but VERY efficient time-wise.
You sound like you're in better shape than me. My husband is a fitness guru, and LOVES P90X. He's in the best shape of his life, and looks amazing. His only complaint is the time it takes sometimes.
Good luck and I hope you guys enjoy working out together!
PS: I have "10 Minute Trainer" too, but for some reason it just doesn't do much for me.