Each person that uses them will have different outcomes/performance. It depends on yer rig (computer & hardware) and how it may be set up. Some have great results, some have sh!tty results and some have O.K. results.
I tried them a while back (before my HDD melted ). They worked well, they weren't great, they weren't bad, they were good. I haven't tried them recently... sooooo, as the saying goes:
"Your results and preformance may vary"
Give them a try... if ya don't like 'em then uninstall them and reinstall the ones you have now. And if ya OC yer Vid Card be very careful since these drivers are tweaked. You may not need to OC it as much.
So... give 'em a try, if ya want to. It's the only way to cure your curiosity.