Hi MMATTAMM,
Conan is a pension's expert - as can be seen from the quality of his reply.
Just a few additional comments that strike me regarding pension contributions - i.e. not commenting on broader financial considerations:
1. What are the chances of your DB plan being still alive when you get to 55? My guess is that it is substantially more likely to be wound-up between now and then! (Frankly, can't understand private sector employers underwriting such promises).
2. If scenario 1 comes to pass, then your concern regarding the compulsion to take all benefits at the same time may be rendered mute. Even if the plan is not wound-up, you would hope that by that stage, the policy makers would have got their act together and removed this archaic and nonsensical requirement (to take all benefits from the same employment at the same time......it's really such a stupid requirement).
3. I suspect you earnings are above average! What is, unhelpfully, unknown is the position with the lifetime limit on pension funds (currently c. €2m). Whilst 1 and 2 above support pension funding, for high earners, the lifetime limit needs to be watched. The problem is that no one knows what the limit will be in the future - which hinders one's ability to plan.