I would call this hike moderate, at least the route we took. We took the Pyramid Creek trail and tried to follow the "Horsetail Falls, Lake Tahoe" Everytrail Guide by Trailspotting. But this gave us an awesome view of the falls with the water rushing by us. And it was good place to rest and eat a snack while enjoying the view.
We got to the parking lot off of Highway 50 a little after 10:30 AM on a Sunday and there were still about 4 or 5 available parking spaces. After our hike it was packed and there were cars parked up and down the other side of the freeway. It's a popular hike and there were large groups and families and pets. So I guess the earlier you can get there the better.