This is a very timely posting, Donna! I'm in the throes of overhauling my cooling system (previous owner never did anything, even the belts are original; 139K miles so far) and I had the very same questions. I've been leaning toward the EMP/Stewart so I will take Mack's advice and include this on my list of parts to get. Thanks to you both!
"The wise speak of only what they know."