OK, will do.
When I first started with O2 there was only one base station in the town and O2 and Vodafone faired slightly better than T-Mobile and Orange due to 900MHz having better range over terrain and better building penetration than 1800MHz. There was always a problem with indoor coverage though, you had to be on the right side of the building facing the mast, and in the centre of town where the buildings have thick stone walls there was no indoor coverage at all. Since then, T-Mobile have put up a mast on the other side of town, so I'm expecting more consistent indoor coverage, and Orange have put up a mast in the centre of town which should help with indoor coverage there. They also have 3G coverage, courtesy of Three, which should take some pressure off GPRS. All in all, the T-Mobile/Orange network just seems altogether better planned than O2 and Vodafone's, so I'm expecting good things but I'll let you know how I get on.