Both Xero and QuickBooks will handle bookkeeping, VAT under Making Tax Digital, and bank feeds perfectly well for a typical small UK business. The honest answer to "which is better" is that the difference is smaller than the marketing suggests — the right choice usually comes down to which one your accountant and your team will actually keep on top of.
We run client books on both. Below is where each one tends to pull ahead, based on the day-to-day rather than the feature list.