With Trace Flag 4136 enabled SQL Server ignores the supplied parameter values for the SQL statement and uses the statistical average for that column in the Statistics Header for the index when it compiles the execution plan. At this point the detail portion of the statistics, the Histogram is no longer used. Trace Flag 2371 was really meant to fine tune through more periodic update the Histogram portion of the statistics. With this being said Trace Flag 2371 will provide little to no benefit for a customer already utilizing Trace Flag 4136.
So If 2371 is updating the not needed detail of the statistics, is the net result a negative one ( over head, etc) and should 2371 be turned off?