The first article seems to suggest that nobody knows how the money will be spent/distributed (this is backed up by the second link).

A rural supernetwork which anyone could use would be a nice idea, but it seems unlikely to happen.

Other articles I read at the time suggested they will pay for cell sites which will be available for the operators to use in the not-spot areas.

T-Mobile and Orange are now a single company. If you are on either your phone will roam onto the others network automatically when your home network is not available. That gives, what seems like the best coverage.

Have recently seen my t-mobile phone roam onto orange 3G, although rare as T-Mobile 3G is probably the best coverage.

Would stay away from O2, their 3G coverage seems the worst and their data allowances are pathetic, quoted in megabytes.

... just like the other 4 of the main operators in the UK (i.e. T-Mobile, Orange, Three and Vodafone)?

I do agree that 02s signal could be improved a little in some areas of the country.
Even some shops and one or two pubs in town you are lucky to even get one bar for signal and yet 02 clams my town has a medium to good signal.

Darren