The $900 million of unsold Surface stock that MS is sitting on says otherwise.
The Surface may be the #2 best-selling tablet (I don't know), but to put that in perspective they've sold
1.7M units since launch. Apple's sold over 150 million iPads.
I frequently have the occasion to visit universities in the course of my work and I have yet to see a Surface in the wild. I'm not sure "all over in the education sector" is very accurate.