Have been with Three (sim only) for many years now, getting decent deals from Uswitch however, the signal has never been brilliant inside the house and frequently drops calls when driving, so need a more reliable network especially in the house.
There’s no 5g coverage here and the two networks that get good coverage indoors are 02 and Vodaphone. Both have decent rural coverage with Vodaphone perhaps having a slight edge. The other perhaps longterm benefits of Vodahone is they have joined Three and will in the not so distant future share masts, which would make them the biggest network operator in the UK.