Any EE mobile customers out there?

Hi i'm looking for someone who is on EE preferably on an iPhone.i'm currently with O2.i'm unsure if i should stick with O2 or go with EE, my upgrade is soon. I have a friend who is on EE and he said that they are very good for signal and overall a great network. Is this true? - pros and cons please.

Don't have an iphone but ee are really good!
The only time I don't have signal is on the tube!