First let me say that whether a car is RWD or FWD doesn't necessarily mean that it has 50/50 weight distribution, that's more controlled by engine placement (front, mid, or rear).
I can go over some of the differences between a FWD and a RWD, but I don't know if I could make a sweeping generalization and say one is better than the other.
A RWD car uses the rear wheels to accelerate and the front wheels to steer. This is good because it allows the steering wheels to do only one job when accelerating in a turn. You have only a certain amount of traction for each tire...let's say you have 100 points of traction for a given tire. When you turn you have to split up those 100 points for each job you want the tire to do. If you only want to turn, you can use all 100 points to turn...if you want to brake and turn, then you have to split the 100 points two different ways. A RWD car also ends up putting more weight on the drive tires under acceleration (weight transfers to the rear of the car).
However, it is not only the two front tires that do all of the turning...the rear tires also help with turning, so with RWD cars the rear tires are asked to do three jobs: 1)accelerate, 2)turn, 3)bear more weight. A RWD also will oversteer for one of two reasons: 1) weight transfer from braking or lifting, and 2) too much power applied causing tire spin.
A FWD car only oversteers for one reason, weight transfer from braking or lifting. With a FWD car which is accelerating in a turn, the front tires are asked to do two things: 1)turn, 2)accelerate. The rear tires are asked to do two things: 1)turn, 2)bear more weight. Since the front tires are the ones that force the car from a straight path, when they exceed their 100 point allotment of traction, the car goes straight.
I don't know if I really explained anything, 'cause my mind is jumping from one to the other, but I hope this helps...if not I'll try and explain it differently.