Does not apply to me, but from what Ive seen:
Pro: possibly more time to spend with the kids and as others have mentioned, more money.
Con: Always the oldest parents....although, this is over played as the age level fluctuates depending upon how many kids other families have. In other words, if a family is at activities with their youngest of five, they might be in the older age group compared to a couple who's there with their first child.
Pro/Con: From my observation, kids with older parents are more mature and smarter. That said, they don't always seem to relate as well with other kids.