Phil Parkin (2/4/2016)
The difference most likely to affect you is the new cardinality estimator, in my opinion. This may mean that you need to tune some queries which previously ran perfectly satisfactorily. I strongly suggest that you do not increase the compatibility level without testing.
Seconded.
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