The PediPaws I bought (with much enthusiasm) was a big let-down.  It was under-powered for my big dog.  The sanding head wobbled baddly and sanded the inside of the guard.  It was very noisy.  The guard made it difficult to see what you are doing, and it was not as simple as the commercial makes it look.

In the end, I liked the results, and I like the idea, but not the product.  Further research on the internet has been encouraging me to try the Dremmel.  I'll try that next.