We have a quaker that also likes to sleep with a toy across his back. We did try at one time to use a happy hut and he became quite aggressive guarding his nest and nipping and screeching if anyone would try to get to close to it. We removed the hut and he again sleeps with the toy across his back. We just make sure the toy has no dangerous ropes, loops etc that he could get hung up in at night.

I do believe it can be different for each individual bird but in my experience I do not like to use happy huts, cozy corners etc in bird cages with birds that are human bonded. It seems to bring out their aggressive or protective nature. I have also heard that in some of the manufacturing of these types of products that birds have been known to ingest the strings off the cloth while hiding in their "huts" and have died due to this.

Again this is just my opinion and I am sure others have had good experiences with them. I just personally don't like to use them and have had bad experiences with them.