Do you mean a defined benefit pension is still better than a DC scheme with 24% employer contributions? And they don't count toward your age related limit for AVCs. Maybe older DB schemes. I'd be surprised if the single Pension Scheme is better than 24% employer contributions.
Hard to do a direct comparison, since a DB scheme insulates you against risks that no DC arrangement, however generously funded, can possibly insulate you against. Hard to put a price on that, and how much you value it depends on your attitude to the risks concerned.
Another complicating factor is that, in the DC scheme, contributions paid at early on in your career contribute far more you your eventual accumulated retirement savings than contributions paid at the other end. So if someone is offered a position with a 24% contribution rate, what that means to his eventual retirement income depends on whether his is now 30 or now 60. (I'm guessing, though, that the positions that carry a 24% contribution rate are fairly senior positions that you reach towards the end of your career, rather than at the beginning.)
The third factor that you have to consider is your own objectives and priorities. As providers of retirement income, DB schemes are very efficient — as in, pretty much all the money that goes in, and of the income and gains earned, is used to provide income for you/your spouse. In DC arrangements, a largish chunk isn't used to for that at all, and ends up being inherited by the next generation. Which is great, if your objective is to benefit your 55-year old children when you die. But if your priority objective for your pension scheme is to maximise retirment income, then you want to be in a DB arrangement.