I have the exact opposite experience with them. Great signal everywhere I travel, rarely lose 3G and its consistently fast.
Gotta agree on the customer service though I can't say any of the providers I have been with have been outstanding in that department
I rarely have issues with signal, however their customer service is some of the worst around.
Last year when I upgraded to iPhone 5 on Orange, I did it online in October. Then the next day I read that people who had pre-ordered the phone still hadn't received it from Orange (this was weeks after release). I did not receive a confirmation email, yet orange instantly took the £200~ out of my account for the phone. Then the next day I rang up and cancelled my upgrade, which they said would be done in a matter of hours - It was not, and I continued to receive automated texts about my upgrade..
2 months later, my contract had finished, and I finally received my £200~ back, but only after I had rang them 20+ times, had them deny that they even took the money, flat out lie to me about all of it, and then finally they asked me to fax (lol?) a copy of my bank statement to them. So I did that (using some online pdf-fax sender which I had to pay £1 for and didn't think would work) and then 2 days later £200~ mysteriously appeared back in my account.
In the end, I had bought a new contract (on Orange - epic fail on my part) from Carphone Warehouse. When I rung up Orange to talk about moving my number across, I got asked where I had purchased the iPhone. I told them it was at CW, and the woman started ranting at me about how 4G wouldn't work because I didn't get it direct from Orange blah blah.. even though it was on their bloody network!
Oh and after I had finally sorted this, I still knew of people who hadn't received their pre-ordered iPhone 5 3 months after release.
Orange are awful, and offer no incentives over other networks apart from 4G, which has bad coverage in my area and is horrendously overpriced!