While modern glass cockpit a/c (with GPS for accuracy) can greatly enhance the situational awareness of a crew and probably make flying a circling approach safer than in older first generation jets, it is still a procedure that is in my opinion
a. not really designed for large transport category a/c
b. much more suited to light a/c
c. a last resort
Of course we can practice it in the sim but the average line pilot gets in the box four times a year if he's lucky and will rarely do a circling approach. I seem to remember it is required in JAA rules if an operator routinely uses them in its network.
If GF has banned circling in their company I say good for them. It's up to the airport authoorities to spend a little and put proper (flyable) instrument approaches on all runways used by transport category a/c. If we can bomb the Taliban with drones piloted by remote from the Nevada desert via GPS etc we can surely manage that.
I know it will upset some people but I believe it's time IFALPA decided to recommend that pilots refuse to fly circling approaches in large a/c. Like the "Black Spot" airfields issue - that might get some action.