Visited Summit Lake for a Friday-Monday getaway, and to watch the eclipse from Summit Peak. The lake, trail and peak was absolutely beautiful.
Fri, Day 1: Road to the trailhead was very rough, as others have mentioned. High clearance vehicles recommended. Hiked up mid-morning to the lake. Saw a few hikers, but mostly had the trail to ourselves. Trail was in great condition. It had some steep spots but overall it felt pretty good. Met some WTA volunteers at the lake who were working on bits of the trail past the lake over the weekend. Found a large camping spot at the end of the lake. Weather was great, there was a breeze so no bugs (even in the trees) but clouds rolled in later in the evening. We had a light sprinkle to heavy rain all night.
Sat, Day 2 - Sun, Day 3: Rain/clouds let up by late Saturday morning and the rest of the day was beautiful. Spent most of the day relaxing by the lake, and drying out the few items that got wet. Saturday was extremely busy at the lake, and there were several overnight backpackers looking for spots. Hopefully, they all found one. Sunday, we day hiked down to the car to drop off some trash. We meant to hike to Bearhead Peak for lunch, but realized at the parking lot that we forgot the water filter at camp, and since we didn't want to run out of water, we made our way back to Summit Lake. We ate ton of ripe blueberries/huckleberries along the way. We also saw a lot of day hikers Sunday. Saturday and Sunday we noticed bugs at our camp spot, but they didn't seem to be biting (much).
Mon, Day 4: Hiked up to the peak to watch the eclipse. Found 8-10 other groups at the peak, but there was plenty of room for everyone. It was a great spot to watch the eclipse, but I was also extremely impressed with the view on its own. Perfect view of Rainier, and panoramic views all around. The trail to the peak was also very beautiful, and a ton of ripe berries. We got to see the work the WTA workers had done - some stairs and trail re-grading to help with water runoff control. Hiked down to camp to finish packing out. Bugs were the worst Monday since there was no breeze, but I'd still say they were mostly no-biters. I think I wound up with two or three bites total over the entire weekend.
Other notes: The toilet at the lake is nearly (like 99%) full. Hopefully, a new one will be built soon so people continue to have that as an option (we were also surprised there wasn't a second toilet - maybe closer to the end of the lake - since there are so many people using this trail). Unfortunately, I noticed a lot of toilet paper behind trees (please use proper burying techniques if not using the provided toilet). However, the view from the toilet is amazing! This hike is great and beautiful, and I hope to take many people backpacking up here, so I hope others treat it well so we can all enjoy it.