https://www.youtube.com/watch?v=w5eMMf11uhM

Skip to about 5:00 to see the part that convinced me a rock strike wouldn't be likely to destroy my expensive frame.

I ended up buying a Santa Cruz 5010, and have loved it. My other bike is a steel hardtail, and I love it as well. I don't think I'll ever buy aluminum again. I had aluminum Stumpjumper and Klein back in the day. Both were workhorses and I put a lot of miles on them. Both ended up breaking at a weld a few years of significant use (but not abuse).