Get a firm offer in writing. Then go have a chat with your current boss about what he's willing to do to keep you.
I don't care who I work for as long as they do what I say.
Harvard Business Review did a study back in the eighties that showed you will move up the corporate ladder fastest changing jobs every five years until you are forty. After forty, you are best off sticking.
Loyalty to a company was rendered, I thought, a quaint notion in the last decade. The company won't give it a second thought if it comes to 'outplacing' you. It isn't like it used to be.