I went to our local B & N store to look at the SG Nook and could not operate it in any reasonable way.
It comes up in the normal Android skin and all that differentiates it are the pre-loaded Nook Apps like Store etc.
The sales lady there could not operate it after a customer, not me, had left in a silly state.
The reading app is hard to find and very basic. The font choices are minimal and useless. There was no way I could see to adjust margin and line spacing.
All in all a dreadful experience, likely to put most new users off.
Coincidentally the Samsung vanilla Tab 4 is on sale for $159 at the Costco store up the road. Avoid!