I think the price is grotesquely too high for the Tablet. Honestly, this will be a huge flop for them if they stick with this price point. People can get a brandnew iPad for 100€ or more less, whilst in the android field you can get similar tablets like this pixel tablet for 50% of Googles fantasy price.
I really hoped for a price below 400€, but for the over 600€ they want i will buy an iPad once my old ones battery is fully dead.
I could never justify spending that much money on an android tablet, specially as i know both, iOS and Android. And for a stationary tool like a tablet (i use mine only at home) in all honesty, iOS is lightyears ahead of Android. Onlyif it is a third of the iPad price you can oversee all the downsides, but for more money it would be self-humiliation to buy the Pixe Tablet.
I am not even sure if the Graphene Team will waste time on supporting the tablet, as the number of users will be very limited or close to zero. The phones were cheaper, so many more possible users that could make a switch to Graphene. But the tablet? I think it will be another one year product of google and will be abandoned very soon.