There are volumes of scientific and medical documentation of sleep deprivation effects. No matter how much of a superman you think you are, you are not as effective and as accurate without sleep as you are with sleep. One of you even stated, "I've worked doubles and triples for years with no problems and hopefully (emphasis mine) never will." Yeah well, what if your child or spouse is on an airplane that hope didn't suffice to give you the consciousness to catch a mistake in time?
Are you gonna say, "Well, yes I had been on duty for 24 hours, but I never had a problem before"? When it comes to other people's safety, it is NOT up to you how much you work or how long you can be on duty. By the time you realize you are in trouble, the plane may have already gone down.
The FAA did not set duty time limits just so they could interfere with your ability to earn extra money. I am surprised that the FAA has not reviewed work records at WN and put a stop to the "24 hours on duty" practice already.