The only time the Sierras have sucked for me was during a backpacking trip. We were at 9600 ft or so and it snowed a couple of inches on us. Now that's not a lot of snow, but this was in late June of last year and there was still a LOT of snow left over from the past winter. On top of that, we still had to hike through a pass that was 2000 ft higher. We weren't prepared for it. So we had to hike back down, and not complete the trip. But like valleycat said, they are beautiful.