You mentioned that you used PacBell in SoCal before you left for the UK. You may be aware that the PacBell network was purchased by Cingular. The Cingular network in CA is now what T-Mobile uses. Therefore, if you were happy with your coverage a few years ago you'll find it even better now if you go with T-Mobile. I've been very happy with them and had great service for 1.5 years now.