@Greaded - just to give you full info in case it changes your choices, you do still get some serious tax wins as a standard rate payer:
1.You get to take 25% of your personal pension tax-free. Which by itself gives you a 5% tax discount on your personal pension, paying 15% income tax instead of 20% income tax even after you get state pension
2.If you do retire early and use your personal pension to bridge the gap, then you'll obviously have your tax-free allowance. Which brings your effective tax rate even lower. If you take £20k out of your pension during those bridging years, with the tax free lump sum and personal allowance you'll pay less than £700 tax. That's a total tax rate of 3.5% which is a huge saving on the 20% you didn't pay earlier!
3.You don't pay NI on pension income (although it's possible that might change, unfortunately). That saves you another 8% if you're a basic rate payer.
Just to give a worked example (ignoring inflation and growth for simplicity - since you get those in either ISA or pension), imagine you saved up £100,000 for your later years, whilst working as a basic rate tax payer
If you don't put it in your pension
then you pay 20% income rax + 8% NI. You pay £28,000 tax
If you do put it in your pension
Let's assume you use it from aged 65, bridging with £20k per year until state pension age, so in those 2 years you'll use up £40k but only pay £1400 tax
Then the remaining £80k you take flexibly over the next 20 years to top up your stare pension. You're paying 15% income tax and no NI, so you end up paying £12k.
The difference
By putting that £100k in your pension, you've only paid a total of £13.2k on it, instead of £28k. You've paid less than half the amount of tax due to saving it in your pension!