I'm pretty happy where I am right now, but if you give me an offer to an attractive position for 20% more money I'd at the very least entertain the notion.
My point is that an offer like that would seem attractive, but two things:
A) The company didn't value you until it was too late. Their opinion of you hasn't changed, just the pay rate.
B) The company now has painted a target on your back as someone that is "in it for the money" and doesn't have the best interests of the company in mind. It's bullshit, but that's now management thinks. Next time a budget cut or RIF is necessary, guess who is first in line?
In both cases, you need to weigh if that's worth sticking around for.
I'm pretty happy where I am right now, but if you give me an offer to an attractive position for 20% more money I'd at the very least entertain the notion.