It's always more secure to always operate the computer under a standard user account. That way you won't accidentally mess up system files or hypothetically download and install viruses etc.
Pros for doing it: It's easy to setup another user, you can always still install from the standard user knowing the admin name and password, and you will have two accounts to check against one another in case some program acts up, and as stated before is more secure.
Cons: None
Basically it all depends on you - it seems to me that some people are real power freaks that can't let themselves be downgraded to standard users🙄, but you really don't lose any control over your computer.