I will always bring my sleeping bag as the few blankets that I did see were certainly not laundered very often - much better in my opinion to be self sufficient likewise my own pillow slip. I always was provided a pillow. The Albergues are generally fairly basic, providing much welcome shelter and a bed - they do get hot at night even in Spring. To me the steady flow of get up in the morning, get dressed, put away your sleeping bag and walk out the door, find a place for breakfast, walk, eat, talk, walk, eat, talk, find a place to sleep, and repeat each day is very therapeutic. It's a very social communal living style where you may or may not eat in the Albergue as some but not all offer meals, there is usually a kitchen but not always kitchen utensils. I generally got a hot shower, I always got a good nights sleep (I'd recommend ear plugs though). I think the secret to Albergues is to be flexible and grateful for what you have, after all if its not to your liking it's only for one night and then you can move on ..... I love it!!
Buen camino