I got a late start on this solo hike, because I live about 100 miles away in the Seattle area and had to ride the ferry. I also thought it would be fun to call back to my Marine Corps days (got out in 2008) and so I carried a 60-pound ruck with emergency supplies. For the future, I would recommend none of these things. It's a fairly challenging hike to begin with, so there is no sense in making it more difficult and risky by (a) going alone, (b) starting late, and (c) adding needless weight.
I have to say, right near the top here, that everyone should be advised about the washout about 1/3 (or so) of the way up the trail (picture attached, although as you know, pictures never do these things justice). If not navigated properly it could be VERY dangerous. I actually got a little fight-or-flight heart palpitation thing going on while I was crossing. It is sandy, maybe 100-250 feet across, and there are areas where the footing is so narrow that you will have to walk with your feet parallel to the bluff. It's not a perfect 90-degree drop, and you may not be killed instantly if you fall, but it could cause very serious injury and/or turn your day hike into an unintentionally overnight affair. While you are crossing, do not try to grab onto the wall as it is mostly clay and will break, and expect minor pebbles and dirt to be constantly raining down from overhead.
Additionally, nearer to the top, there are parts where the snow is fairly deep and the trail narrow enough that losing your footing could also turn you day trip into an overnight ordeal.
Overall, it's not entirely a life-or-death hike, but I would only encourage intermediate to advanced hikers to travel this one. It's not for kids, not for the out of shape, and not for the faint of heart.
I don't remember what this hike was rated in terms of difficulty, and maybe it seemed harder because of my pace and the extra weight, but this time of year the hike is definitely in the "strenuous" category. The first third is soft, dry ground and a mild to moderate grade, the second is alternatingly steep and occasionally rocky, and the third is pretty brutal, particularly with snow and mud and often steep grades. There are points in the last 2/3 of the trail where the grade must be 35-40 degrees for sustained periods. I don't think my pulse dropped below 100 BPM for two and a half hours, and at the top the sweat was pouring off my head. For these reasons I would recommend bringing lots of water (I had a 100 oz. CamelBak) and extra food.
I saw about 7 other people on the way up, in 3 groups. One group advised me of the washout and told me to take off my YakTrax, and that poles would be better. I would NOT advise that for crossing the washout. I think YakTrax are essential, and poles would be more dangerous, if anything, because they occupy your hands when you need them to steady yourself or brace (but not grab) the wall. YakTrax will also be COMPLETELY essential near the top, as there is lots of mud and snow to be traversed. I might have spent an extra 15 minutes slipping around and getting dirty without my YakTrax, gaiters, and old tennis shoes, all of which are good ideas for this one.
On the way up, there are several "false" endings near the end of the trail, where you think you're done and there's another quarter mile before you think you're done again, only to find another quarter mile and so on. Because I started so late (4 PM), I almost didn't keep going all the way to the top for safety reasons (I didn't want to cross the washout in the dark, for one), but I'm glad I continued to the top, because...
...danger/logistics aside, this is a BEAUTIFUL view. There is a cool WWII plane-spotting cabin (apparently 1 of 2 still standing of the original 13 in the Olympics), the inside of which has been vandalized with various insipid amateur philosophy, and even some vulgar anti-Bush scrawlings, just in case W finds himself atop Pyramid Peak in the next few years feeling good about himself. You will find you are REALLY high up, and the views of Crescent Lake (and others nearby) as well as the snow-capped mountains are rivaled only by that of, say, Mt. Pilchuck on a clear day. Because it was already dusk by this time, I only spent 10-15 minutes up there, but under better circumstances I would have stayed for a nice lunch and some good pictures.
I ran all the way back down, which was hell on my knees with the pack and the 100 oz of water, and I even bit it once (mercifully I survived with only a little gash). All told, it took me about 80 minutes to get up, and 40 minutes to get down, but most people at a normal pace should plan on closer to 105 minutes and 75 minutes, respectively.
There is a cool dock overlooking the lake below the "parking lot," which makes for some more good pictures, and after the laborious hike up (and down), it would be a shame to miss the easiest view of all down there at the bottom. There are also picnic tables and a fire pit for groups who want a scenic BBQ to put a cap on the hike.
All in all, I would describe the difficulty as 'high' to 'very high', the view as 'exceptional', the hiker traffic as 'low', and the danger as 'moderate' to 'high'.