All I can say is IMHO, and my years exp dealing with Oscars, your experiences may vary. 
......and he can comfortably keep in his sized tank for years to come.The important thing is that the op has ended up with a fish that they like and will hold their interest.
Agreed, I forget not everyone has mts and may consider upgrading a deal breaker.......and he can comfortably keep in his sized tank for years to come.