I have no information as to how effective these files really are. I haven't even tried them myself yet.
Update: Based on some further research with these files and some email I have received, I am removing the link to these files. I have reason to suspect these files may be a hoax.
Several reports now suggest that these files are little more than Motorola's MathLib file in disguise (both the 604 and 603 files are essentially identical). As a result, they may indeed speed up some benchmarks, in the same way that Motorola's file would.