Go with one (framed) 60" mirror. It's neater, brightens the room, and gives you a larger view of yourself and your outfit. Two mirrors are more fussy, break up the view, and are rarely an improvement over a simple single mirror.

I think it depends on the room layout, mirror style & vanity lighting you’re using.

One thing to keep in mind if you're going with Theresa Peterson's recommendation is location of any power outlets, if you have any - need to make sure that they remain accessible. You can always hang the mirror(s) above them, but then the mirror(s) may be too high. I have that issue with my currently remodeled master (this is the "before" photo) - because of the power outlets, and because each mirror needs to be centered with its respective faucet, I cannot do wider mirrors (even though I have the space, theoretically):

Also consider the possibility of using two mirrored medicine cabinets, which add a ton of storage!

Hi, I’m debating this same issue. What did you end up doing? Do you mind sharing a photo of the outcome?