Barrons has some details that Cliffs misses and vice versa. I'd say it's about a 90% overlap but you never know when material from that other 10% might show up on the exam.
Depending how patient you are, I've put together a set of notes that combines Cliffs, Barrons, KBB, Examkrackers (merged together from notes that other users have posted on here - Bangity, scsc7211, etc). It's 60 pages long but extremely thorough and will cover all those extraneous details so you only need to review one material source and then use the notes to get the rest.