Sims Limbsaver Recoil Pads - Made of Sims shock-absorbing Navcom material . . . . . . .

Recently heard these are the best for reducing recoil.
Thinking about trying unless someone recommends something better.

Would appreciate any advise from those who are using, especially regarding which "version" to purchase:

1) Screw-In Replacement Pad
------- Are these easy to install?

2) Slip-On Pad
------- Sounds easy enough.

3) Grind-to-Fit Pad
------- Sounds time consumptive.