you'll regret the decision and in 6 months you will be gone, 1 year max. whatever dissatisfaction that led you to interviewing elsewhere will come back in full force at your current job once the euphoria of your pay bump diminishes and, frankly, you should have been asking yourself why your current employer didn't think you were worth "something better" before you went in to resign
not to mention your current employer will remember how close you were to leaving so if it comes down to you and someone else for a promotion, guess who gets the job? and if it's down to you and another to be laid off, guess who is on unemployment? best thing you can do at this point is hitch your wagon to your current boss that got you the counter offer because if he leaves the company or your division I guarantee you will be the odd man out.
worst thing anyone can ever do in their career is accept a counter.
Spot on....I think the stat is about 75% of people that accept a counter and remain at current job are gone within 6 months.