What happens in most DB schemes, a pension is calculated when you leave based on your final pensionable salary at date of leaving and the service earned to date.
This pension will then increase at CPI to a max of 4% per annum between date of leaving at the 1st of January before your Normal Retirement Age.
Depends on a number of things as to whether you should transfer to your new scheme:
1. Funding position of DB plan - if below 100% on the Minimum Basis then is likely your transfer value would be reduced - not advisable to transfer in this case.
2. Your own risk appetite. Advantage of DB scheme you can see what level of benefit you will get at retirement. DC scheme - you are going to be taking the investment risk on - with no guarantee of what your pot of money will buy you at retirement.
You can transfer this money at any time between leaving and retirement - so if you change your mind in ten years time you can do so then.
Personally, if it was me I would leave where it is, and start the DC scheme from afresh - so you'll have a combination of the pensions on retirement