We did it in 2008 and booked online. I wouldn't consider it a must see attraction though.

Yes, tour was in Japanese but you can use an audio guide. You start off in a building to watch a video to get oriented, followed by the tour which is essentially a walk along the grounds; all outside. I don't recall being able to see inside any of the buildings. There are however, a few architecturally interesting buildings along with a bridge & moat and the trees are pruned beautifully. So, there are a couple of very nice photo opportunities.
If was kind of funny though how the guards grouped us along and paced us.

Also felt the Kyoto tour/grounds were more interesting.