Mobile coverage - more important than tariffs?

Recently I switched mobile operators from 3 to Vodafone. In the past I tended to switch to take advantage of the most appropriate package for my usage. However this time the key driver was better coverage. I'm fed up with flaky (and seemingly getting worse) coverage from 3 in my house - despite promises of improvements. This location is flagged by 3 as 'excellent coverage' but of course that applies outside and in-building coverage is variable at best. I switched to Vodafone because I know it works well here and generally I haven't been disappointed so far. The only big coverage problem with Vodafone, as with all the operators, is coverage on railways. This is still terrible on the line I use, across all operators.

Real world coverage is for me a more important consideration than the specific tariff deal. The mobile operators all 'appear' to offer fairly similar coverage, certainly if their marketing is to be believed. However in reality there are huge differences, even in cities. The problem for consumers is that until you test the network coverage in your home or wherever coverage is important to you, you never know what the reality will be because operator coverage claims just can't be believed. Borrowing a friend's phone on your desired network, pre-purchase, is a absolute must but I think often overlooked.

It never ceases to amaze me how variable coverage still is, so many years after launch. I hope that the operator network infrastructure sharing deals will do something to address this but in this age of cost cutting I wonder ...

Just one request to Vodafone - please fix your online billing system. It's been broken for weeks and doesn't show accurate data.