The 10 miles of solid rock kills ya at Mt. Whitney. The sand gets ya at Mt. Langley.
The yack trail out to either Army or New Army Trail rocks and rolls and sandy. Once you get to about 12,300', 1 trail become thirty routes to the summit. The steeper more direct ones are best.
I would take Army Pass, it more direct and it eliminates the 300' back to New Army Pass, which is a royal pain in the rear end. There are a couple small blocked sections near the top of Army Pass that are easy to navigate your way through.
I second this - take the rocks/steeper way up (as long as you are comfortable scrambling a bit). We took the scree (stayed to the left) and cursed loudly the whole way up.
The summit is WAY up there compared to how it looks from the bottom. We thought we were at the summit about 4 times before we were there.
I also second the advice to take Army Pass (rather than New Army) that 300+' of up from Army Pass up to New Army looked AWFUL by the time we finished summiting. I was never so happy to not have to hike back up.
As far as being 'blocked' I didn't feel there were any blocked sections of trail when I hiked it two weeks ago (7/28). There were one or two places you moved around or through the rocks a bit, but no exposure or sketchy moves. You really didn't even need your hands at all. Otherwise just watch footing a bit on looser rocks on the trail - and it's just that... trail all the way up right now.
