I chose to go private because:
A, i didn't want the hassle, embarresment and torment the NHS seem to put obese people trying to gain funding through.
B, I wanted the best of the best doing my op and wanted the aftercare to make sure i succeeded with my weight loss.
I paid 10.5k for mine and like some others have said its worth every penny !
Seems that with the NHS its a bit of a lottery filling the criteria for WLS and you dont really get to choose your surgeon or where you have the op, if your lucky you get a good surgeon.