Haha! They are great when they notice things...especially when they only notice the good stuff! My husband is quite observant but won't say a word when there is something off unless it's so funny (smeared eyeliner all over my face after a good cry) that he can't control himself!
I remember my 90 year old grandma's advice when I got married:
Don't point out anything bad about yourself because whatever you keep saying about yourself, your husband will eventually believe. Men are much more observant than they let on. If you have a small chest (um, thanks Grandma!), and keep complaining over and over, he will one day think, "Wow. She really is small-chested. I never noticed that."
Sometimes I wonder...