I recently had to make the same decision. I had an offer to do an MS on a very interesting project, but chose to go work instead (I had a competing offer with a good position at a hardware company). The big kicker for me was: How do you do effective research in an industry you've never worked in? The majority of professors I see went BaSC->MS->PhD, and frankly, are horrible. The best professors? They've gone and worked in industry for at least a few years. And their research reflects this, and is usable. It is also worth considering that some companies will pay for you to do your master's part time. Granted, this might be an M.Eng, not an MS, but HR probably won't know the difference. This is the route I'm going. If in a few years I want an MS or MBA, I'll go back to school to get it. I don't see myself in this field in 5 years so it's less of an issue for me.