HAVING & Bind Variables

Had an odd one come across my desk today. I have seen Bind variables used in the WHERE clause thousands of times. I have seen Binds in the SELECT lists hundreds of times. I have seen it used in the HAVING clause zero times... until today when it turns out it was causing a performance issue. With the Bind variable in the HAVING clause we were seeing an execution plan with lots of Full Table Scans and 12+ second runtimes. When editing the query and using a literal in the HAVING clause we saw 100ms or less performance and very efficient Execution Plans. I chased down Bind Variable datatypes to make sure no implicit conversions were sneaking in and wrecking my execution plans. Found nothing there so continued with a 10053 trace. The 10053 trace for the Bind in HAVING was 4X larger than the one with the literal in the HAVING. I won't go into a full description here, but I can tell you the Bind/HAVING scenario was causing the optimizer to at least CONSIDER a lot more possibilities when it parsed the query. The only difference in HAVING processing I could find was below (see highlighted line): HAVING clause with bind variable in expression:

HAVING selectivity: 6.9706e-05  -> GROUPS:  1
    SORT resource      Sort statistics
      Sort width:         178 Area size:      156672 Max Area size:    31457280
      Degree:               1
      Blocks to Sort:      16 Row size:          258 Total Rows:            496
      Initial runs:         1 Merge passes:        0 IO Cost / pass:          0
      Total IO sort cost: 0      Total CPU sort cost: 10995455
      Total Temp space used: 0

HAVING clause with literal expression:

HAVING selectivity: 6.9706e-05  -> GROUPS:  1
    SORT resource      Sort statistics
      Sort width:         178 Area size:      156672 Max Area size:    31457280
      Degree:               1
      Blocks to Sort:       1 Row size:          271 Total Rows:              1
      Initial runs:         1 Merge passes:        0 IO Cost / pass:          0
      Total IO sort cost: 0      Total CPU sort cost: 10795355
      Total Temp space used: 0

I rewrote the statements to logical equivalents that kept the 2 bind variables but eliminated the HAVING clause. They all now run in