I like to balance rewards in my campaigns around the characters, and not just a flat amount. It makes sense to me that in a encounter dealing with traps and thievery, the thief's skills would be called more to the fore, and that they would receive a proportionally higher cut of the take. In universe is also makes more sense to me. It does have potential to create in game tension between characters, but that can also be a good thing, in measured quantities.

One problem I've had with reward systems is that my players are far, far too miserly. Simply put, my players would sooner starve to death than spend one cent of gold on food. It creates some problems for getting them to spend their gold, and not just hoard it to ridiculous levels.