It's encouraging to hear that the crowding at the cables was less...maybe the "fad" has died down a bit, or maybe the news of crowding or temperature has slowed things down a bit.
I'm not a fan of clips and harnesses on those cables, but if it makes folks feel safer, and they don't cause congestion, that's great that they're being careful. For the ones that force unwilling, too-young kids up the cables, I'm sure it's a good thing especially. Not as good as leaving the kids behind to do kid things until they're old enough to WANT to go up HD, but good nevertheless.
Ten hours is pretty quick, at least if you're including your time at the top. If that's just hiking time, it's pretty reasonable, and feeling tired on the return is normal (except for the few that figure Half Dome is an "easy" hike, unlike us mere mortals 8^). We're usually dragging by the time we get past Nevada Fall, and ready for it to be over. If you figure out a way to eliminate that and be zippy and refreshed the whole distance, let us know...8^)
Well keep in mind, this was a Sunday, and it was about 11am to noonish. By the time I started my departure it was about 12:30 to 1pm and it still wasn't that bad. All told I encountered only about 4 or 5 people going up, maybe about 15 going down.
My travel time didn't include time spent on the summit which was about an hour. I hit the trail head at 550am and got back to my car around 450am (not including that longish walk to the lot). I probably could've done it a hair quicker as I said if I didn't have to stop so blasted frequently in the last 1.5 to 2 miles of the return trip. Basically the body started giving up on me on junction where you can keep going JMT or take this branch down toward Vernal Falls itself. I figured, two miles left, I got this made... riiiiight. Leg muscles suddenly couldn't take the pounding any more and I had to stop about every 15 to 30 minutes. Weird thing was hydration wasn't an issue. Only thing I can think of is that maybe I need to sleep more before the hike (which is a problem because I get too excited to do these things and can't sleep), or force myself to eat more food along the way.
Now I did encounter one of these kids going up on that harness I referred to and I swear this kid was a machine. I could tell from the look on his face that he was pretty comfortable and he moved up those cables with relative ease. I was quite amazed. The other people I encountered with clips were also moving up with relative ease. This was just an all around different experience from last year.