The recessed aftermarket keys allow you to use very little bolt to achieve the lift, vs twisting down your stockers till the bolt is almost if not completely tightened up to gain the lift. So yes, there is benefits to buying the new keys, less bind and torque on the bolts equals better life and less chance a torsion bolt from snapping.
But, I just went thru another driverside axle upper boot. The second one in little over a month. The new axle shaft will be in tomorrow for pick up. Luckily, the shaft I bought comes with a lifetime warranty, no questions asked.
I know that the Torsion Twist is doing this, creating the ribs of the boots to rubb constantly against one another as I am driving which in turn is wearing the boot ribs to a thin wall. The sad thing is all the TT I did was 1.5", so I do not know how you all are telling others that 2" would be OK. Especially after I am going thru cv boots like water. And this is with the new lift keys I bought. Even at 1.5" of TT lift, it is increased drive line angles to wear these boots out fast.