There is some really good info in this thread and the best way to compile it is as follows…
Mid Arm systems do very well at 3.5" of lift and under 12" travel shocks. Of course they can all ride smooth and handle well on the highway, but it is the wheeling aspect that will get you. If you go outside of the above parameters, the axle steer effect of having the long travel shocks are on mid arm or short arm system becomes really obvious. Also, with the more travel you demand, the more bushing distortion that is required out of the mid arms or short arms since they are 5 link systems front and rear. With good long arm systems, all of those things go away and you can then let the vehicle stretch it's legs even further, be more durable and have a better on highway ride.
It really comes down to budget. A good long arm system will always ride better, should handle better, and certainly do better off-road. The real issue becomes, does it fit in your budget?