Hi Mark,  Most of the conversations I've heard about FSA result retention surround 2 topics: A) capacity tolerance, and B) usefulness of result set.  Capacity tolerance is simple enough to understand -- how much space are you willing to allocate to the result sets.  When it comes to usefulness of FSA results -- how "old" is "too old" is the question.  Some admins will perform weekly comparisons (say Sunday to Sunday).  So it's normal for them to keep results for at least a week.  Some will run monthly comparisons.  Usefulness is very subjective and really depends on how fast your cluster is changing.  I've seen FSA results going back a year or two from customers' production clusters.  Hope this helps.
Is there a recommended Result Set Retention approach or it is a question of how much storage capacity you can afford to allocate? Thank you.
FSA reports: Result Set Retention