One minor dislike: we do wish the pre-cut lengths were a little longer for the 6mm size. It comes in a 5.5 m length (18 ft) and we wish it came in a 20 ft piece. But that is a minor dislike.
The pro cord is made of nylon. Go to our climbing sling review to read about the difference between nylon and Spectra and Dyneema.
You can also buy this cord in the following lengths 2 mm, 3 mm, 4 mm 5mm, 5.5mm 6 mm, 7 mm. We like the 6mm length the best because of its strength, durability and ease of untieing. If you are alpine climbing or trad climbing, you might like the 5 mm or 5.5 mm size. However, for big wall climbing, we find it is harder to undo the 5mm size after weighting it.