Having a made a decision to change jobs less then a year ago, I understand the difficult choice.

Unfortunatley, either way, you are going to have doubts and for awhile wonder if it is the right thing. While extra money is nice, you have to try and figure out first what is going to make you happy, and second, what is going to be the best for your future (and the happiness does play into what is best).

Good luck, with whatever you decide.