I regularly get botox for my crows feet, and sometimes anger lines. I'm early 40's and only have crows feet to worry about from too much tanning a few years back.
Pro's: Quick, low-pain(I feel the prick of the needle, that's it.
Cons: Takes a few weeks to really be noticeable. Cannot help directly underneath the eyes. I sometimes feel a little nauseous afterwards, but that is not severe and the feeling is gone the same day.