My linux desktop had it built in, its nice to know if i'm sitting here and my CPU's spike for a long period I can check my processes and see whats happening, i can visual monitor my dual cores and see that they are both be used for something, mine also has temperature info on the CPU's which is probably obtained in a similar way and it helped me figure out the best desk configuration to keep my computer cooled. Is this all useful, i don't know, but i like having it, makes me feel powerful. BTW statistically sampling it will provide data even if each individual sample might not be representative. ;)