I love the ability to create calculated sets.  There is so much power in being able to define a set using an aggregate condition and then being able to go back to a row level and evaluate in/out of the set.  (and in fact, you can do a row-level calculation first, then aggregate that calculation to define the set, then do another row-level calc to determine in/out -- this kind of power and flexibility boggles the mind! I love sets!)

Having said that, I would like even more power and more sets!

How about being able to define a set, or rather a series of sets, using a single calculation?  For example, lets say I have a data set with patients who have one or more admissions to a hospital (each row of data giving the patient and admission date) and I want to define several sets based on the number of admissions.

Right now, I would need to define multiple sets with different conditions:

Patients with 1 admission -- Condition: COUNT([Admission Date]) == 1

Patients with 2 to 4 admissions -- Condition: COUNT([Admission Date]) >= 2 AND COUNT([Admission Date]) <= 4

Patients with 5 or more -- Condition COUNT([Admission Date]) >= 5

But what if I could define a "Super Set" with a series of subsets based on a single calculation

IF COUNT([Admission Date]) == 1 THEN SubSet("Patients with 1 admission")
ELSEIF COUNT([Admission Date]) >= 2 AND COUNT([Admission Date]) <= 4 THEN SubSet("Patients with 2 to 4 admissions")
ELSEIF COUNT([Admission Date]) >= 5 THEN SubSet("Patients with 5 or more")
END
 

I would envision the UI presenting this, perhaps, as a hierarchy of sets, where each subset worked as a regular set works now for the purpose of combining sets, and filtering.  Other options may be possible as Tableau continues to expand functionality around sets.