I found Three to be excellent in general, just lacked a little in signal coverage at times. Never was bad, but once or twice struggled a little out in the countryside.
That said, their data connection was awesome - I had a 12 month SIM only deal from them, which was a great deal at the time, but moved to Full Monty SIM only with another great deal at the turn of this year. I will almost certainly head back to Three towards the end of the year, especially with the imminent arrival of 4G![]()
Will they be giving 4g with unlimited data by any chance?!