I can see that... one of the obvious problems that we can find some case where the meta-ethical systems go against our moral intuitions. This sometimes leads to attempt to make the meta-ethics incorporate this case (and then some more), but I feel it quickly becomes rather obvious that we cannot come up with any consistent system that also satisfies our intuitions. I'm a bit pessimistic philosophers will resolve this problem soon...

On a more happy note, I have found Kant's reasoning very useful for my own personal opinion-making, by constantly reminding me that if I find X about, say, genetically-modified food, nuclear energy etc., I really need to make my opinion in terms of a rule that doesn't include the particular case, and I try to think what this same rule would mean for other opinions I hold.