The Martin D-18 is a very fine guitar. At least, most of them are.

That being said, if one is endowed with a brain, one does not buy a guitar without examining it first, or at least having some knowledge of the reputation of the luthier. I have seen lousy Martins. If you buy a guitar on the basis of brand name alone, then you are as stupid as you are trying, in your typically suave and sophisiticated way, to accuse me of being.

Go sit on your own guitar, you mindless twit!

That's alimentary, my dear Martin!