MRAY  1.5.7 is a much needed update to an overall excellent application. The folders I usually compare used to take 7-8 min, vs. 25 sec now! Although I own a copy and I am pleased with it, the folder comparison performance prior 1.5.7 was a problem for me especially with very large folders.

In my experience and for my purposes DeltaWalker is the best comparison tool at steal price. Support for comparison over http & ftp will be a great addition.  
(Version 1.5.7)