Taking into account that you are not required to have Photoshop for that... Yes, I guess it's quite good.
Plus, if you don't want to manually add borders to 20 icons in order to have all the standard formats, I guess it's ok again.
Furthermore, if you want to have them called as they are supposed to by current THW / WC3S / Blizzard standards, you can have that done by W3IR.
And "detailed 'documentation'" it's called "Readme.txt"... Over 30 KB of it... I wrote that myself...