cuz your friends an idiot
but no seriously, omega drivers are modified so the author just tried to make it either faster or have better image quality, thats bout it, might run faster or have better IQ on some systems but certianly not all, it doesnt work at all on my pc for instance, i get bsod's
for some the reference drivers or beta's do better, it really just seems to vary wildly, theres also many other modified drivers out there like DNA..etc, you have to run benchmarks before and after each driver to find which you like better, there is no definite for everyone.
also could be just in your friends head that its better too