Ive run one for about five years now. With a Bosch 044 inline, C5 z06 and 60lb injectors regulator it made 740/810 with 1000cc of water/methanol spraying.
The main downfall of the setup is since it is not boost referenced, the more boost your run the smaller the injectors act. My injectors are 60lb at 43psi fuel pressure, so at the 58psi the regulator shows at no boost the injectors act like 72lb'ers. By the time you are at 15psi boost, the fuel pressure is back down to 43psi at the injector, so the injector is back to about 60lbs.
I once ran a rising rate regulator and return with the bosch 044 thinking it would stretch a little further and it didn't. If I had a bigger pump it would have for sure though.
Moral of the story, if your injectors are big enough, and you tune for it, it works great. For given injector size and big fuel pump, a rising rate regulator will make a lot more power.