They are amazing. I have read them three times now lol
I will though admit I love the language and histories of middle earth so very much enjoyed the Silmarilion. Some of the unfinished tales move very quickly while others more slowly but I'd say they are worth persevering for if you find it hard going as some of them can put a different light on things in his other works, Things like more info on the wizards and Rohan at its founding etc.
I'm part way through the extended histories of middle earth, if you found the silmarillion hard don't read those as they might kill you, amazing to read though.