I've been to Spy Rock a number of times, but only went to the actual Maintop summit once. The AT no longer travels over the summit, although you can reach it easily with a little bit of a bushwhack. There is a section of trail still visible on the summit, as well as the rock cairn.
The AT has been rerouted and doesn't go over the summit...the path is still there, but you need to look for it.
A hike on a day in May.
My wife and I hiked this and nearby Priest in one long day loop hike. Hot, humid and stormy late in the day.
I actually woke up to my alarm at 2:30! At 3:00 AM on Sunday morning I started my 3 hour drive out to the mountains. At 6:30 AM I started my hike with a temperature of 26 degrees (sweet!). It was a great day, cool and crisp, and no crowds.