Comment revised upwards ...

I bought these headphones for my Xperia Tablet Z2.
The sound is really not bad compared to Apple earphones "basic" I was using.
They hold in place (with the basic tips) despite their shape and size.

I go to China next month, 2 * 10 hour flight will allow me to better appreciate the noise reduction, I will put this comment to date.

No idea so far of the tablet autonomy down with activated noise reduction.

EDIT
I go back to edit the comment after 20 hour flight.
Noise reduction, which I found disappointing home compared to street noise is quite efficient plane. It's pretty amazing. This is hardly one still guesses the engine noise. And even without listening or movie or music, you can "enjoy the silence" with silent headphones in ears, it works too. So relaxing.
In fact, more noise is regular, the more active reduction is effective.

By cons, as I feared, it lowers the autonomy of the tablet.
I'd say about twenty% of thumb ...
EDIT