In my opinion the best lightweight cot on the market is the Helinox Cot One. Very smart and easy setup (2 minutes), strong, stable, and very comfortable WITH A MATTRESS. At around 4.5 lbs most backpackers would not use this cot because you now have the “big four”––tent, sleeping, bag, mattress, and cot––instead of the “big three.” The cot is the same size as a packed 2-person tent. But if you're strong and the rest of your gear is super light, this cot might be a possibility. It would work great for canoe camping or motorcycle camping.
Used with a good mattress like the Exped Synmat 7, the combination of Cot One + mattress is literally twice as comfortable as the mattress on the ground.
I got the Helinox cot specifically for kayak camping and love it. I also use it for car camping for the times when I just don't feel like wrassling with bigger gear like the Camp Time Roll-a-Cot. I got my camp setup time down to 15 minutes with the Cot One, Kelty Trail Ridge 3 tent, and REI Campbed 3.5––ultimate comfort in a small package.
I got the Cot One over the Thermarest Luxury Lite because the Thermarest is much harder to assemble (it has something like 34 parts), is clearly less comfortable (manufacturer says you can't break it because you bottom out––that's a hint about how well it supports your weight), and reviews complain about it breaking. It's lighter than the Helinox, but the Helinox beats the Thermarest in all other respects.
The price of the Cot One is ridiculous ($300) and sales are very rare.
I paid $240 on sale after watching the internet for months. No regrets––I love this cot. Beautiful piece of engineering design.
Watch this video and you'll be convinced––especially the part where the guy walks right across the cot with no harm done.
https://www.youtube.com/watch?v=W3tQids996Q