I PennHip'd both of my females at four months since I was planning to breed them and wanted an early indication of their potential. I think the process is much more objective and precise than OFA but not as widely accepted. One of my females scored in the 80th percentile range and was finally OFA'd "Good". I have seen a number of dogs with OFA "Excellent" ratings with hips that are not as good as hers. My other dog scored in the 90th percentile range and received an OFA of "Excellent". PennHip requires three x-rays under general anesthesia. The cost for me was about $450/dog. I still needed to do the OFA raising the total to about $800/dog.
Penn Hip has prevented me from spending lots of money on a couple of puppies for training that did indeed end up dysplastic. I wouldn't dream of sending a dog off to a pro that wasn't 70% or better. I like to do it between 5-6 months. My vet does give me a copy of the OFA view to send to OFA as well for a prelim from them.
Here's the question.... if you really want to know your dogs hip status would you get a test down where the results are figured out mathmaticaly or by an opinion? Math doesn't lie, Penn hip is the only way to go.