Comfiest curler set I've ever slept in. It's even more comfortable`than sleeping in headband curls (which are soft, but never feel secure on my head, These stay plenty secure so long as you tuck the ends in on a roller and roll all the way up to your scalp). I wouldn't say that these curlers are so soft that you can't feel them in at all, but they're still soft enough that I can lie on top of them comfortably. I'm a flexi-rod enthusiast, but I have to be really careful to position those where none of them will be in places where my head hits the pillow if I want to have any hope of getting a decent night's sleep. These require no such consideration and have no affect at all on my sleep. And there appears to be little trade off between comfort and their curling ability. I've tried rolling my hair when it's bone dry without any product and have gotten nicely defined curls that could last at least 6 hours before falling into waves with a little hairspray. I've tried rolling my hair when it's just barely damp and have gotten tight curls (*too* tight IMO!) that lingered until I brushed them out on the second day (or approx. 36 hours later). The way that works best for me though is to spray completely dry hair with a little beach spray before rolling it. This gives me the longevity of rolling it damp but with the more natural looking curls I get when I roll it dry. That set will last me all day long and still look wavy (though not curly) the following day.
The only thing I don't really like about these curlers is their size. They're made up of a 1" cube of foam inside of a cotton sleeve with a bendy wire inside that allows the curler to stay in. That cube compresses to a much smaller width when you roll it and you can only use a small amount of hair per roller (like a .75" section), so there's little you can do to vary the size of your curl or how curly you want your hair to be. It'll either be pretty curly if you roll it dry or Shirley Temple curly if you roll it damp. Also it takes quite a few (at least 20 for me) to do your whole head. If you have thick hair, you'll probably need more than that.
Overall great curlers! They won't replace flexi-rods as part of my nightly routine as those do better for the loose type of curls that I prefer, but these will definitely be what I reach for when I want tighter curls.
My hair is long, thin, layered, straight, dry and color treated. I try to keep heat styling to a minimum but I can't just wash and go either. Hot rollers don't hold a curl in my hair. Velcro rollers work ok but I can't sleep in them. I bought 2 sets of these foam rollers several years ago so but I didn't use them often. I don't know why I stopped because they are great. Probably because I thought the next curling iron or set of hot rollers would be better.
The best thing about them is you can easily vary the type of curl you get. You can also use a setting spray if you want. Using them on very damp hair and sleeping in them will produce the tightest curl. Using many rollers and and wrapping small sections of twisted hair tightly will produce springy coils. Using them on nearly dry hair, wrapping larger sections of hair more loosely and sleeping in them will give you big, loose curls. The curl really lasts too, even in my very difficult to curl hair.
The rollers don't take long to put, just wrap & twist, in but I don't think they'd be very effective without leaving them in overnight. The downside is they obviously don't work as quickly as heat styling appliances. The other short fall I see is that the cushion part of the roller is fairly short which I compensate for by just using more rollers. They produce curls, not volume so I often set the top of my hair in large velcro rollers. They are very comfortable to sleep in and easy to remove. I bought mine at Walgreens and I just saw them on sale, $6 for a set of 18. Sometimes, old school works better. It may take some experimenting to find out what works in your hair but I definitely think these are worth a try if you have the time.