Not much to say about a drive up, except that it was fairly crowded at the top. The road up is pretty poor, with narrow spots and several rough patches and dips. So low speed is advised.
We did enjoy the summit house for hikers, and did see several through hikers (AT) resting at the top. We were in Shenandoah earlier in the year during peak through hiker time, and was again here at Greylock. The ones I talked to were weary, but in good spirits, probably due to the fine weather, and nice pit stop on their journey.
The view was pretty clear, and we did enjoy taking photos at the top.