Generally I don't read my S/L Kings. Exceptions to this are like Six Stories and my recently aquired Eyes of the Dragon. Six Stories because most of those stories I had not had the opportunity to read and EotD because I have heard there are significant differences in the text.
I wouldn't try to read Insomnia as I have heard it is full of mistakes such as misspellings and the like due to a goof up in the wrong copy of the book being used for the final printing.
Any questions related to limited editions