Hi,
I don’t remember if the glitchy issue of quaternion interpolation was present in JME2 since I moved to JME3. But in JME3, you can have a look at the class jme3test.model.anim.TestAnimBlendBug that shows the bug: when blending animations, some bones are moved very weirdly using slerp, but they aren’t using nlerp 
Indeed!!
That’s gold, thank you very much.
It’s faster and fixes bugs 
What else?
Also, I guess it’s ok for animations because it blends for short periods, but nlerp has a non linear speed, so in some cases slerp would be the way to go.
Anyway thanks again!
yes exactly, I tried with longer blend times and it’s not as smooth as slerp, but well, it does the trick 