I agree with those who've already offered their comments - it depends on the tartan and also your own personal tastes. Many tartans can be pleated to more than one stripe as well - and you may like one but not the other.

Looking over my four knife-pleated kilts, two are to stripe and two are to sett. I would not change any of them from one to the other, though I'm sure they would equally nice.

Discuss your options with your kilt-maker. Chances are, no matter which decision you make, you'll like the results.