Less, I imagine. More natural flex--more pain. But don't know for sure--it was nearly 30yrs ago, too and I would think things have improved a bunch. He said then grinning, "use it now, before it turns to mush." I usually get into the Rockies at least once a year, DIY for the lion's share.
At the time, it was just a trade-off, a little more flexibility to climb in the hills, but more pain. Heel and lower were crushed. Are you wearing it down from an old injury?
Personally I do as little as possible to keep you going with maximum flexibility--you can always fuse more later as you wear it out. An accomplishment, like wearing out a barrel...:)
