From my experience, the "PhD or not" depends entirely on the field being studied. In chemistry, the PhD is the union card that allows you to enter industry at a higher level and allows advancement if one's lucky/good to quite high levels. The BS/MS folks enters with lower ranks and face a ceiling about the point where PhD's enter. Similarly, the MD has all sorts of advantages to those who have studied medical-type fields at lower levels.
Conversely, nobody hired CS PhD's outside of think tanks or academia as far as I can tell. Similarly, engineering PhD's seem tracked to academia.
There are some companies that hire CS PhDs , or at least have divisions that do.
Google, of course. Xerox. A bunch of big DoD contractors have R&D departments. Video game companies have been known to pick up graphics focused Phds. Pixar.
There are lots of engineering PhD's in industry, but you have to pick the right industry. For example, there are many other electrical engineering PhD's at my current workplace (a microprocessor design company), but PhD's were very thin on the ground at my previous job (a software startup).
It's actually quite hard to move from industry back to academia as an engineering PhD. According to some academic friends, unless you've been publishing tons of papers while in industry, you're looking at an adjunct faculty position at best.
Conversely, nobody hired CS PhD's outside of think tanks or academia as far as I can tell. Similarly, engineering PhD's seem tracked to academia.