Posting this from NJ and I agree with Senator. We took the EWR/HNL flight in BusinessFirst for my 50th last year and the service was just perfect. It is a long way and since your coming from the UK would advise a layover or stop in NYC for a day or two to rest up,
CO really has a nice product and the chicken dish I enjoyed for lunch is still memorable as was the hot fudge sundae they prepare for you.
Save up the money and do go and if you get to Kauai you must take a helicopter tour of the Napali Coast. We used Blue Hawaii Helicopters and purchased our flight on DVD and its not a canned version either as our voices and comments can be heard on it!
MAHALO NUI LOA!