I've seen 'em both break. I don't have a big database though...those parts are pretty uncommon. I think I have seen many more campy strada cranks break than titanium spindles...

And Hi-Lo flange hubs? I'm admitting that I just know the story, I don't have any actual data to back up the story. Conventional wheels are plenty strong. I have Rolf wheels that resurrect the hi-lo concept, though. And the Bontragers on my wife's bike also have hi-lo hubs (I think that these are rebranded Rolf's, though. Right?)

I just noticed that this sounds like I have two Hi-Lo hubs on my bike...not true. Just the rear hub...