My sister did this with her rescue (we think she's a Finnish Spitz). Her results came back on Wednesday. All her major breeds were unidentifiable, and the only minor breed that showed up was Border Collie. They did send her a notice and discount to re-do it once they get more breeds in their database.
I've thought about running Woody and Maple through it, but, with Maple, I'd rather be ignorant than have her info come back with PB in it. No, I'm not against PB's, I know several VERY loving ones, but, my Home Owners Insurance would drop us~! And, for those of you in states where PB's and other breeds are banned, would it/could it be used against you?
If its just a tool, I think its great, 'cause I've always had MUTTS :-)