It is an often hot topic amongst Scubaboarders, but the DIR vs NON-DIR discussion can be analyzed by simply viewing two different pictures of some idiot sporting ear muffs.
Picture 1 - The NON-DIR ear muffs

Notice:
1) White Ear Muffs, anything not black will get you tossed from this DIR crowd.
2) Look at the drag those Ear Muffs would create while walking.
3) Look at this idiots face, he hasn't shaved in days.
4) Speaking of drag, look at those teeth.
5) The glasses on crooked and cross-eyes will probably keep him out of any fundies class.
Picture 2 - The DIR ear muffs

Notice:
1) Black Ear Muffs, good enough to make even George proud.
2) Total streamlined design, with a single spring strap wrapping around the back of the head.
3) Look at this idiots face, clean shaven. This reduces drag also.
4) Teeth are pulled and glasses yanked.
5) Cocky pose to boot - TRUE DIR fashion.
J
Picture 1 - The NON-DIR ear muffs

Notice:
1) White Ear Muffs, anything not black will get you tossed from this DIR crowd.
2) Look at the drag those Ear Muffs would create while walking.
3) Look at this idiots face, he hasn't shaved in days.
4) Speaking of drag, look at those teeth.
5) The glasses on crooked and cross-eyes will probably keep him out of any fundies class.
Picture 2 - The DIR ear muffs
Notice:
1) Black Ear Muffs, good enough to make even George proud.
2) Total streamlined design, with a single spring strap wrapping around the back of the head.
3) Look at this idiots face, clean shaven. This reduces drag also.
4) Teeth are pulled and glasses yanked.
5) Cocky pose to boot - TRUE DIR fashion.
J