PS (not even going to try and spell it) is a german METRIC (so you americans will have no idea ) unit of horsepower. It is roughly equal to DIN horsepower. The conversion of DIN hp to sae isnt direct but to the best of my knowledge sae is roughly 11% greater than DIN hp. I would expect 722PS at the wheels to roughly dyno 800rwhp on a US dyno.
The dyno in my sig is actually in PS, Im going to get another dyno run in SAE so I can better compare it to your local figures. Will see for myself what the difference is then.