I have had a few phone calls recently from people coming to Anglesey asking about 3g broadband coverage in camp sites etc. I am afraid that the answer is not good. The best places seem to be around the Menai Straits which has some signal over spill from Bangor and Holyhead where the ferry terminal seems to be a hub.
From the coverage maps below alll the main operators seem to cover these two areas however, the 3 mobile map does suggest coverage in a other areas as well. This is born out from some clients who I know use 3 mobile broadband rather than a BT land line as the signal speed is better!
The covearge maps are below and I would welcome any coments about specific areas of Anglesey where you have experienced good or bad 3g mobile service.