Your thoughts? Experiences?
Depends on the recoil. Depends on the sighting system.
I like the softest pad I can shoot without the stock and recoil pad compressing so much the scope hits me in the head.
Example: I had 2 different 700 XCRs, one in .375 H&H, one in .338 RUM. I had 2 scopes ... not merely identical, but the same scopes got mounted on both rifles at different times, one a Leupold 2.5-8X, the other their 3-9X. The .375 would occasionally brush me with either scope but never gave me a hard hit. At least 2 of 10 shots with the .338 RUM would smash the scope into my skull hard enough to ring my bell. (I even eventually tried a scope with over 5 inches of eye relief and still got hit.)
Both had a lot of recoil but both were manageable so far as my shoulder was concerned, it was the hits to the head I didn't like. I got rid of the .338 RUM after a while. In hindsight, I suspect I could have made it work if I'd gone with a little stiffer stock and a firmer recoil pad. Yeah, it would have hit my shoulder more, but I was not to my tolerance level there. It might have saved my noggin.
What I picture happening is that under very heavy recoil with a soft pad, you've basically got an inch less eye relief with the scope than you'd have with a hard plate. If the stock is flexible under extreme recoil, as I believe the XCR stock was, eye relief is compromised even further .. regardless of what the scope starts out with.
Tom