First, the grips are from Patrick Grashorn. I think they were the first pair he made for that model.

The "enhanced" model has (If I remember correctly) has a better recoil spring system (I think a full length rod), the scalloped area behind the trigger guard was to prevent frame cracking, the elongated hammer and the longer beavertail. The serial number will end in an "E". I'm going from memory, so anyone feel free to correct me (I might do so after I have some coffee!)