Knowing the details of your group's DB plan will help guide your decision (and other's advice here).
For instance, is your DB plan a traditional pension plan that will pay an annual benefit upon retirement until death. Or, is it a Cash Balance DB plan that will pay a lump sum plus interest credit upon retirement.
As always, the devil is in the details.
For what it's worth, my group is starting a cash balance DB plan this year. We specifically chose this over a traditional pension because it was a cleaner exit upon retirement. That is, the group is not on the hook to provide an annual pension salary once a member retires. With the cash balance plan the "defined benefit" upon retirement is simply the participant/group/corp's contributions plus an annual interest credit (e.g. 4%). That's it. Clean and simple. In addition, if we were to dissolve as a group, merge, become acquired, etc. we can terminate our cash balance plan and roll the funds into our IRA/401k accounts to be self-managed.
Hope this helps.