I agree w/ yer bro-in-law, if after renewing the system fluid leaked out of the connection at one cylinder, that's the fault of the mechanic, not the design of the brakes
spend as much as you like, but an old truck is an old truck and in good condition will drive, ride and stop as good as necessary, a complete chassis swap is the only way you'll "get the truck to a more comfortable ride" if you envision "comfort" in 2014 terms
Bill
