No company is perfect, so it comes down to what one serves you best. I was with O2 for 14 years and was very happy until they started increasing plan costs so I moved to Three and have been with them for the past year with zero problems. I'm now considering moving elsewhere for a better price. One mans junk is another mans treasurer.
Exactly not one of them are perfect and will probably never be!
I've had the least problems with Three out of all the networks,
My worst experiance was Meteor /eMobile a couple of weeks ago worst mistake i've ever made totally unusable data seems to be a known issue in Meteor customer care.So i'll be moving back to Three as soon as i can.
Hopefully you have a good experiance with your new provider if you do move
Also is O2 and Meteor really up for sale or is this just rumours?