You have to consider what purpose you are acquiring them for though, and to what kind of drums.
I guess those who are less happy with them experience some deviation between their initial expectations and the purpose they are using them for.
The two plies are “closer linked together” because of the oil, which gives a more compact feel and limit the vibration of the plies.
Therefore, they also remove certain high frequencies and limit the sustain.
My experience is that they work well (and primarily) on lower tunings, to achieve that kind of EQ`ed rock or metal drumsound when you are just playing in the room (without mics or anything).
And for that purpose, I find them great!
I guess they also do work as well on recordings, when seeking that certain “thumpyness” in the sound, although I haven’t got much experience with that myself, yet.
