I have Power Grips, and I quite like them. They are MUCH tougher and more durable than a plain nylon strap. A plain nylon strap would shred to oblivion in relatively short order.
Also, let's put things in perspective: You've already willingly spent, what, $300 dollars on clipless pedals and appropriate shoes? And you're objecting to $35 for Power Grips? Isn't that a little silly?