Vesper Peak might be the most difficult but rewarding hike I've done to date. I would highly recommend that you be comfortable with scree navigation and boulder hopping. But wow, what a view. 

Cloud Inversion finally after just reading about it or seeing others post photos !
halfway up the last granite wall is when I really came out of the cloud/mist/fog. Beautiful conditions either side. Almost what you want in an ideal hike - shade and low temps while climbing and then sun and warmth and great mountain view at the viewpoint :)

Since the technical parts of this trail have been well reported recently, here are a few other things I found noteworthy today (and some slightly different hike pics):

The biggest obstacle on the trail today was this week's heatwave. Most of this trail is in the sun and starting early really seems to be key. I started up at 8:30am and managed to hike all the way to Headlee Pass before the sun really hit the trail which helped a lot. 

I hiked out around 2 and some of the groups coming in looked like they were suffering a bit. Some also appeared not to have enough water. It would be wise to carry a filter here. I had to refill water today quite a bit more than I usually would.

Route finding can be challenging in some of the talus fields in the basin below Headlee Pass. Personally, I didn't really find the cairn placement helpful here and got off trail a couple of times. On the way up there were four other hikers and there was some nice crowd sourcing of the route when it was confusing. On the way back down I used GPS to stay on track. I found route finding on the upper slab portion of the peak easier than the lower basin.

There were quite a few blueberries higher up on the trail. Above the lake there are some beautiful wildflower patches, particularly lupine. On the slab scramble I found a pair of ptarmigans and got to watch them for a while (second pic). There were a lot of pikas today, particularly in the morning.

There were no bugs all the way up to the top, and then for some reason there were a few hanging around the summit. Nothing was bad enough to be annoying though. 

I wandered over to Vesper Lake after the peak. The water was nice and cool, but the lack of shade shortened my time there. 

There were a moderate amount of people on the trail for a Monday, not a lot, but enough that there was always someone around. Everyone I came across was in high spirits and super friendly. 

Prime time for this hike, although pretty hot on the way down.  Berries are ripe down below, no snow to deal with, and no bugs.  

Road:

Good shape and only a few miles.  There's one gouge close to the TH that may be too much for a sedan, but there were many of them parked at the TH.

Trail:

For such a popular route, this trail is very rough with very little easy cruising.  No blowdowns (since most of the trail is not in the woods), but lots of big rough rocks to deal with.

Headlee Pass:

The lower 1/3 is the worst, with slumping and loose rocks to contend with.  Up higher it's in really good shape with nicely defined switchbacks that are well benched into the slope.

Granite scramble:

A lot of fun; just don't be in a hurry.  Watch for cairns for general guidance and find your own slopes and cracks to make your way up.  There are beautiful little flower patches grouped around water seeps that you might happen across.

Started hike at 8:30 a.m this hike is no joke , this is a grill, views are stunning but on a sunny day be prepared with loads of water and prepare yourself to cover up anyway you can, the heat becomes relentless, your lips will dry off multiple times, the hike itself is a constant incline really hard on thighs and once you reach the lake than you really need to push for the last most hardest part, be prepared this is harder then Mailbox Colchuck