Satisfying and Satisfactory are slightly different in meaning. Satisfying means something is nice, pleasant, good etc, whereas satisfactory means that it is fair - or meeting minimum requirement. So saying something like "this is a satisfying dinner" is higher compliment than "this is a satisfactory dinner". Also, satisfying can be a verb, where as satisfactory is always adjective. So you can say something like "this satisfies" where as satisfactory cannot be used in this way.