How does this coverage checker compare with your experience?
It allows you to quickly select any of the networks, which is a lot more convenient than having to search separately in each of the network coverage checkers.
They do ask for feedback if your experience is different from their prediction, so that they can adjust their predictions.
I set my phone to 2G-only and tried a speed test on the O2 "My network" app. Had to disable data sync just to get it to be able to start the speed test, otherwise it just sat there failing to load the configuration settings.
Result with full 4 bars was 64kbps down, 33kbps up, 2598ms response.
Last weekeknd I was in a valley in Somerset with no signal on any of the 2G networks. Didn't try Three, but the prediction was even worse for them.