the Performance Horse Registry is part of USEF. The advantage to registering is that they do DNA testing on your horse. Your horse will also maintain its same USEF #. PHR also has nice year end awards that you can participate in.
PHR is not a breed registry it is a performance registry, they do not do inspections, or have keurings.
There is a lot of information on COTH about American Warmblood Registries, just do a search.
Most people are more concerned with how well a horse performs rather than what registry it may be included in.
Proud of my Hunter Breeding Princesses
"Grief is the price we all pay for love," Gretchen Jackson (1/29/07) In Memory of Barbaro
The American Performance Horse Registry is also part of a USEF program.
It's only open to domestic bred horses and is intended to recognize the performance of that group of horses.
It is not a registry and no papers are issued. In order to enroll you need some sort of documentation to prove the horse is domestic. They do have rankings by age group.
The documentation can be breed or registry papers but it's open to all domestic bred horses regardless of what division the horse shows in. There is no split for H/J, eventing or dressage for example.