I was not sure about crate training either, but during our research phase, all the books we consulted said that crates not only made training easier on the humans, but also served as comfy safety zones for the dogs, as others have also mentioned. So, we decided to crate train Lerwick. I'm so glad we did, because he really does see his crate as his "spot." In fact, he's napping in there of his own free will right now as I type this.
Once we decided on crate training, we had to decide what type of crate to get. Did we want a wire crate that would feel very open, or one with plastic sides that would give more privacy and feel more "den-like?" We went with the wire crate, and I'm very glad we did, because Lerwick likes to be able to see what is going on. We first tried putting his crate in a quiet corner of the living room, but we found he always lay in a spot where he could see the whole room, so we put his crate there, and he started sleeping in it by choice.
We make sure his crate is always available to him, so during the day we have it out in the living room, with the crate door open so he can go in and out as he pleases. At night we bring the crate into the bedroom with us and shut him in the crate while we sleep. That way he can be with his pack, as Jaynie said, while still being confined. He goes right to sleep and doesn't make a peep until 6:30 a.m. when he whines to go outside for his morning potty trip.
Much like Jaynie said, we feed Lerwick in his crate, and whenever we give him treats, we send him to his crate to receive them, so he is pretty good about going into the crate on command these days. And, like I said, he goes in there to nap or just relax sometimes.
We have also found that the crate helps with car trips! Lerwick doesn't like riding in the car, and would whine and pace and try to crawl up me and hide his face against my neck. He wouldn't sit still or lie down, it was a real pain going anywhere. So, we tried putting his crate on the back seat of the car and putting him in it, and now car trips are no problem. He paces the crate twice when we first start driving, then lies down and is relatively calm the entire trip. He even willingly gets into the car on his own now, instead of struggling and trying to get away like he did before.
As for housebreaking... Lerwick is 5 months old and we are still working on the housebreaking. I honestly don't know what we'd do without the crate, and bear in mind that I am home all the time. He is 95% reliable, but still sometimes decides it isn't worth the trouble of asking to go out when he has to go #2. Just two days ago I caught him when he was about to go in the back hallway. So, he doesn't have full access to the whole house yet, because I need to be sure I can see him and get to him in time if he decides to make a bad toilet decision, LOL. So I definitely don't think he'd make it through the entire night without an accident. Without the crate, I suspect I would be cleaning up dog mess every morning when I got up. Lerwick also likes to chew on a corner of the carpet by the stairs, and also chew on the cat's scratching post, so if I wasn't cleaning up dog mess, I'd be cleaning up vomit piles of carpet fibers and cardboard scraps.
And, as others have said, the crate is also useful for those times when we need to get him out from under foot for a few minutes, or when we leave the house on errands, or whatever.
I do hope that eventually we will be able to trust Lerwick with the run of the house at night and when we are out of the house, without having to worry about potty accidents or destructive behaviors. But even then, I will still keep the crate around for him to use, because he genuinely seems to like it.
