A bit of advice I got from a long ago mentor that I never regretted taking: never entertain a counter-offer. His reasoning was that 1) if it was important, the

A bit of advice I got from a long ago mentor that I never regretted taking: never entertain a counter-offer. His reasoning was that 1) if it was important, they would have taken care of you before it got to the point you quit, and 2) they now know you'll leave, and you should probably assume that they'll be eliminating whatever it is that made them desperate enough counter-offer to keep you, and 3) accepting and offer from a company then standing them up isn't good for your reputation, and people do talk.