Thanks for this, Pete. Well-written and accessible article, as are most of those on Cyclingabout.
The writer recommends against the Mavic XM719s that I had fitted on my Raven at the start of this year. Peter White offers them on his wheel builds, and my LBS, which supports a lot of MTB/enduro competitors, say they've found them bombproof. On crazyguy, I have read about rim failures with the XM721s, the lighter variant.
My experience with the XM719s has so far been very positive, but the amount & type of use I've given them is some way short of expedition touring. If I was doing expedition touring, I'd use a heavier rim, maybe the current (2015-onwards) Velocity Cliffhanger.
I'll keep a close eye on my rims, though, esp before, during & after any long tours!