I hadn't really thought about crate training before the current pup. It wasn't really "a thing" when we had my old dog. This time around the breeder recommended a crate and I looked into it separately anyway. I'm so glad I did. My dog was toilet trained within a week or so, and was sleeping 11-3ish and then until 7. Then he quite quickly made it all the way through the night (although I didn't push it as I didn't want him to "fail" at all).
He now goes in his crate for bedtime, and also when I am eating my evening meal. He goes and waits in his crate as soon as he sees me get a plate out. It's really sweet. If I go out for a short time I pop him in there as well. He's in a large crate as a medium dog so he doesn't look cramped.
He has a medium crate for travelling in my car too. But I'm going to try him loose in the boot once my boot guard arrives.
I'm a crate convert. as with others, I wouldn't like to leave my dog in one for hours on end in the day, particularly the smaller crates, but it's useful for overnight sleep time and short bursts. My dog looks very comfy in there; he stretches out and sleeps on his back.
It's amazing how much a crate can hold! We had 2 extra large crates joined together with the side doors removed and the adult Rottweilers would share one of them cuddled up together, leaving the other completely empty except for the water bowl.
I use a crate during the day for my 15wk old pup who goes in himself (see pic, he's gone in there now for a bit of peace). I've never used it at night though, I prefer him to be in a big comfy bed and he's been clean overnight for weeks now.