Comparing an RGT to a PRS CU24 is like comparing apples to ice cream. There really isn't much tonal similarity at all. I actually had both an RGT3120TV and a '94 PRS CU24 simultaneously and they really were VERY different guitars. I even put a MegaSwitch "P" in the RGT to get the same pickup selections as the PRS rotary 5-way.
The PRS has a "thicker" sound. It's just overall warmer. It may be the difference in the construction, since the RGT has a maple chunk running all the way through the body and the PRS is just a set neck. Body woods aside, both guitars are built differently. The difference in the mass of the tremolos may have some effect too. Regardless of why they're different, they really DO sound quite a bit different.