New motor sounds sloppy

Does anyone else notice the 4.0 sounds sloppy as hell when gassing but once it reaches higher rpm's it sounds good?? I don't remember my old 2006 sounding like this. Maybe I am used to the silky 3.5 that was in the RAV4 but damn wtf gives? Is it piston slap? BTW this motor has less than 1000Kms on it... Not sure if this has been touched on here. It certainly likes the higher revs.

 

The engine not brake in give it another 10 km, my was the same, it drag like something pull , but after 6000 miles it went away.