It is truly amazing.

Yes, the permits go fast. If you participated in the 6thFan competition, you should have a leg up on everyone else, though.

I highly recommend renting canyoneering boots (with neoprene socks). They are very rugged and have great traction on the wet slippery rocks. You can do that hike in old tennis shoes or just about anything else, but your feet will thank you if you spend the money to get the canyoneering boots.

If you go with at least one other couple (or person), you can use a shuttle car. But you can save yourself a couple of hours after the hike is done by paying for a shuttle service to take you to the trailhead at the beginning of the hike.

It's all downhill, but it's fairly long, so you want to be in decent hiking shape (so it's not an ordeal and you can really enjoy it).

Some people like to make it a day hike. That way you don't have to carry camping gear. We did it as an overnighter so that we wouldn't feel rushed to get done all in one day (my wife isn't a particularly fast hiker). If you do camp, I would recommend trying to get one of the middle campsites so that the first day isn't too long (it's nice to break the hike up into roughly half each day). So campsites 5-7 would be good for that.

You have to pack out EVERYTHING that you bring in. That means you should take those little foil bags in case you have to take a dump.

I would highly recommend this hike. I'm very glad that we did it.