Will a master's open up any doors that wouldn't be open for a Stanford grad with a good resume? Wait and see. In your case, I'm extremely doubtful that a master's will make any difference whatsoever. And getting one now is premature optimization. Wait until you find yourself trying to get a specific kind of job, but failing, because the jobs are being snapped up by people with advanced degrees. Then get a master's. I…
A MS usually requires about 30 credit hours, or 10 courses. Do these accelerated MS programs have the same requirements? Sounds like earning the degree now may shorten the program's duration.
I'm doing a masters in applied math, and not having to do a thesis would sorta ruin the whole super independent part of it. I'm looking forward to doing cool research that I want to do. It will probably suck towards the end when I'm finishing the details of my thesis, but right now its exciting to dream of things to research.