Interesting replies. Thanks everyone for keeping it subjective.
I think the US/NAM has it about right. 18,000/FL180. Done!
Fine for Oz/NZ to have a standard of FL110, but this varies I think with low pressure situations.
And for those who fly the world over, I think setting QNH on descent when cleared to an altitude covers it all.
Pilots don't generally like waiting to set things when they know they need setting. Plus the verbal set, X-checked etc that goes with it is better done higher up than lower down when getting more and more vectoring, speed control etc. in my opinion.