I was hoping that if you can find some time, you could add in all the relevant route photos to the East Buttress page. They're difficult to find in the general Whitney photo page given it now has >500 photos.
Did the East Buttress route over Memorial Day weekend (2004). Here are a few points to supplement the good description on the route page:
We did the route following the SuperTopo description of it. The difficulty of P1 and P2 depends on which left facing dihedral is taken. The one on the right (recommended by ST and one we did) is 5.6; the one on the left is 5.8 (have not done it). The face moves on P3 which ST describes as the crux of the ("standard") route (rated 5.7) are probably much easier than that. The piton (2 actually next to each other) on that pitch are useless as they have been banged in to the point where you cannot get a biner or even a thin cord thru. the head. Route finding is mostly straightforward (though not trivial - route meanders on and mostly off the arete). If you are following the ST directions, note that the route veers off to the left as you move above P7. P9 should put you on a talus field below a small tower (tower is on right; talus field on left). As you near the top, pitches 10 and 11 (as described by ST) have many variations. Some of those can put you at the base of some fun terrain. Our P11 put us on a ledge 30 feet below the summit that had several ways of topping out visible - from a 5.7+ finger crack (short) to a (probably?) 5.9 fist crack (opted for the former).
Protection: Light rack with stress on cams rather than nuts. Cams in the 0.5 to 3 inch range - most pro was in the 0.75 to 1.5 inch range. Pitches are easy but tend to be long (most are over 140 feet; many over 160 feet). I'd imagine that backing off the route would be pretty gear-intensive (unless you'd be willing to downclimb it).