I am a check airman at a regional airline. I have flown with 400 hr pilots who were excellent pilots and picked up rj flying with no problems, and I have flown with 4000 hr pilots who struggled and almost failed out. The amount of time that you doesn't really matter.
However the 1500 hr rule is mandated by the government, by people who know nothing about flying. There is nothing we can do about it. We just have to live with it.