3's reception is just as good if not better than the other providers (maybe excluding EE). But EE's customer service is a joke and I prefer not to have to make a complaint everytime I want something done.
Currently on 3 SIM only for 12 months, £17 a month for unlimited 4G data, texts and 200 minutes. Includes the roaming thing they've got and whilst I don't go abroad that often- it's a nice gesture that a phone provider is doing the free roaming thing without being told to by Ofcom so I felt like supporting that too.