Why was the quadrail given to you? They typically aren't cheap. So was it an honest to goodness gift, or just crap that the giver wanted to get rid of?
IMO, a picatinny rail is about the worst surface you would want to hold onto on a rifle. They are sharp enough to cut or abraid your hands under the right conditions. You may have noticed that they sell covers for picatinny rails, so that you can actually use a handguard covered with rails. They also add weight.
I have Maguls on my ARs. They are functional and durable. Of course, I also am a strong believer in the KISS principle, and my ARs are built accordingly.