How sure are you that the pension, or a reasonable payout therefrom, will be there when you are 57?
Many companies have or are eliminating pensions. My former company stopped. Offering it to new employees, and is in the process of reducing its contributions to existing accounts for those still working. I expect a buyout offer within 10 years.
So, you may hold on for something that will be eliminated - like the proverbial end of the rainbow. Since you already have an account, if you were still working when they eliminate it, they'd probably have to offer you some sort of lump sum buyout. I don't know that for sure, but they can't just keep the money.