My wife and I have different last names, both of us choosing to keep our own last names when we married. (Although we toyed with taking on a new, outlandish last name for both of us to share, like PowerMaster.) Other than the occasional rude question about why we would have such a strange arrangement (some people are stuck in the 1950s apparently), it rarely raises an eyebrow.
Except on the financial end. After all these years of spouses having different last names and parents having different last names than their kids (or stepkids), you’d think this wouldn’t be such an issue. But, more than once, we have had to straighten out a financial problem that occurred because of different last names and lazy administrators/professionals.