We purchased the trip from Las Vegas to the West Rim in advance through Viator (note: in addition to what you pay online in advance, there is an additional $20/person fee that you pay when you check in with the tour operator). We had purchased both extras: the helicopter + boat ride, and the SkyWalk. Early pickup, and long line to check in with Gray Line. On the drive out, the driver kept repeating how we would have exactly 4 hours to do everything, and it would be rushed, and we should not be late. We assumed that since they sold us these activities, there would be time for it all, as long as we moved quickly.
We followed the instructions to the letter and raced from one activity to the next. First there was a looong line for the helicopter + boat ride. Computer glitch. But finally we were on our way, and that part was awesome.
Then we took the shuttle bus to the SkyWalk, and the disaster started. First, there was a very, very long and disorganized line (with some people cutting). They told us the hold up was due to an insufficient number of lockers (as no packs or cameras are allowed). That turned out not to be true. The long line was due to a big crowd combined to many staff members taking lunch break at the same time. After about an hour in a first line, they let us through to a waiting area with the lockers. From there, more lining up: they would call people by numbers. Except, we had not been given a number. There was a lot of confusion and many groups went ahead of us. After about 30 minutes, we realized there was a problem. The staff in charge had gone to lunch and a bunch of people had been let into this area without number. There were about 50-100 people in our situation. It was very chaotic. We asked to be given a number, and they said no -- had to wait for a supervisor. With a lot of begging and waiting, finally a supervisor arrived, but he was completely unhelpful. The easy solution would have been to let the people without a number go through. Rather then apologizing and believing 50 people in front of him, he said he would give us a number that would get us to the Skywalk after about another 20 minutes ("to make sure we did not get ahead of anyone else"!), or we could get a refund. Many, like us, opted for refund, but when we went to the cashier, they refused to reimburse us because, although we had our tickets, we did not have the receipt for them (since we were given the tickets by Gray Line). It was infuriating!
In the meanwhile we were hungry (no time to eat), our daughter was crying from hunger and everyone's frustration, and it was past time to be back at the bus for the ride home. We rushed back to the bus (after waiting for the shuttle) and asked the driver to wait while we would at least grab some food with the lunch coupons (which were part of the package) to eat on the ride back. But when we went into the store to grab our lunches, they had closed the register! Not only they would not take our coupons, but they would not even sell us food, unless a manager signed our coupons to approve the exception. We had to run to another building, find the manager, who finally signed the coupons and helped us get our food. We were late to the bus, the driver scolded us, and all passengers were upset thinking it was our fault that we were late. It was humiliating.
In summary: Skywalk is severely mismanaged, but Gray Line oversells activities without allowing enough time to enjoy them. Four hours should be enough without huge lines, but it is absolutely not enough when one spends 3 of those hours in lines due to crowds, glitches, silly rules, and mismanagement. Gray Line knows this very well, and still they push to sell those activities.
Result: A beautiful day with the family at the Grand Canyon turned into a nightmare.