Just bear in mind that the query stats DMV is dependant on the plan remaining in cache. If the plan is recompiled or aged out, the stats are lost. If a plan is never cached, it won't appear in the query stats DMV at all.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability