I got an offer with a much better salary than my current salary. The written, official offer was sent to me via email. I accepted it via email (nothing signed yet) and one day after giving my resignation letter to my current employer, she (current employer) gave me a counter offer with basically the same terms as the other company, except that I have 1 extra week of vacation per year in my current company.
I had tried to negotiate that extra week at the beginning of this process because it's important to me but was told I couldn't get it because everyone gets the same amount of vacation. Because I originally was offered more money than I'm making, I was ok with letting that extra vacation week go; but now that my employer matched the offer, that extra week becomes more appealing.
Would it be ok to try again to negotiate that week after I already told them yes? I don't see myself staying in my current company just for the extra week, but I'm wondering if I should try to get it. Somehow, because it's not money it doesn't seem so bad to me, plus there is new info on the table since I told them yes, namely the counter offer from my current employer. Would it give a bad image to bring it up again with the new company?