I have the earlier four volume set. They were actually double-sided dual layer discs. Many people had problems with these types of discs such as freezing or skipping. I was one of the lucky ones that bought all 4 sets and had no issues. Each set contained 8 movies, except for volume four which had 6. They came with two double-sided discs with two movies on each side. The compression wasn't high at all. The quality was very good.
I will only get "It Ain't Hay" if they will offer that individually. I don't double dip with Abbott & Costello. I only do that with the stooges.
The 4 volume sets are now out of print, so that means that Universal does indeed have plans on re-releasing the movies.