i have a tmobile one and wouldnt recommend it, their poo
i also have a 3 one for my daughter, since i have my fone with 3 i get the internet half price with them so hers costs me a fiver and the signal and image quality online is great, wish i could get out of the tmobile contract, it'd cost me £13 a month for both mine and my daughters then rather than 25 for both and me having crap coverage