Don, I have both purchased ones and home made versions.
The advantages I see from the home built variety are that they essentially cost next to nothing and take but a few minutes to make. If you need a particularly narrow or wide one for some purpose or other, it's easy to do. Plus you can make them stiffer, or more springy as you choose, by making the fingers longer, wider or thinner as you may need.
I have read on a number of occasions that folks make theirs using a bandsaw. I never do that, always make mine on the table saw. The cuts are more consistent that way.
Try a couple of your own first, then if you aren't satisfied, buy a couple.
OK, fess up...which one of you clowns stole my sig? It was right here a second ago.