I only use it as a last resort, or if I'm just making some crap arrows that I don't care about and I am willing to lose. Sinew is much better because it makes a much stronger bond due to it shrinking when it dries. I just can't get as tight of a bond with art. sinew as I can with real sinew. So much for modern technology....
But if the fake stuff is all you've got, then use it. And like everyone said, the strands are quite big, but you can split it down into much smaller strands that make a neater wrapping job. It is waterproof, which is a big advantage over real sinew.