Well here's my tuppence-worth.
I've had problems with Orange - customer service dreadful.
First, I was on the phone to them for 1½ hours. This was three calls in total, and included two disconnections (from a telecomms company!). Anyway, I received no contact within the agreed 48 hours so thought I'd use it as leverage against a good deal on an upgrade to the GNex.
Or : "What phone are you after"?
Me : "Galaxy Nexus"
Or : "Do you mean the Galaxy Note"?
Me : "No, the Galaxy Nexus"
Or : "Well, we have the Galaxy S2 or the Galaxy Note"
Me : "No, I want the Galaxy Nexus"
Or : "We don't do that phone"
Me : "OK, thanks. I'll request a PAC next month and go with another provider then. Bye".
I suspect that the reason they have delayed its release, and it's already been mentioned here, is not because they want to make sure it runs and works on their network, but because they want to be sure that it works with all of their branding rubbish. Even if the branding wasn't too intrusive, there would always be the nagging feeling that I wasn't get the proper ICS experience.
I have two phones (mine and my partner's) on the same account and am hopeful that I can get a cracking deal on the Nexus on Orange. If not, then bye bye Orange.
What I would recommend is to not accept the first deal from any network. Go to them with an idea of how many minutes and texts you would use and wait for them to come with an offer and say "Don't need that many, and don't want to pay that much. What else can you do?" Always works for me.