"Loosely" is right - I was bored to tears. I guess I just wasn't ready for it at the time.
I'm currently reading "The Machine Crusade", the second book of the earliest Dune prequel trilogies. I find it a lot more interesting than some other prequels that are out there.
I've already finished the first set of prequels, but I only got as far as book 4 (Children of Dune? It's been awhile) of the regular series. It was starting to get a little tedious. I can see why only the first was made into a film.