I put a set of wheels built with Shimano XT, aluminum axle hubs on my touring bike for a 3,000 miles tour. Four hundred miles of that route was over dirt and unsurfaced roads, and over 500 miles was on cobble or sett stone roads and trails. That was 7 years ago, and several thousand more miles ago, and they are still running as smooth as the day I put them on the bike.

I believe the concern for using aluminum axles in a touring environment is overblown. The main criticism of the XT hubs was the freehub, not the aluminum axle. I'd ask the question: How many people have actually had a problem with aluminum axles?