I've been up parts of it, never the summit. Depending on your approach (the worst is from the souteast), you could expect a lot of loose rock, steep grade, and some hellish heave. You can also expect inlcement weather most of the time. When I got to the snow line in July, it was nasty slushy for a long ways, and I was soaked up to my armpits from all the sloshing and splashing.

Your best bet is to come in from the north. The transition is closer to road access thata ways, so you don't have to pack in a week just to get to the base. If you come in from the Hoh side, expect to wear rain gear most of the time.

When are you planning an ascent? I wouldn't bother going up until mid July at the soonest if I were headed that way again.