Thoughts so far:
I've enjoyed the game and am still really excited for the full release. I got maxed out pretty fast (gear & levels) and haven't really had much to do except PvP anymore so I've put it down so I don't get burned out. I think getting at least 30 hours out of the full release is a worst case.
The 'not good' stuff:
The controls can be pretty clunky at times, imagine an even clunkier Mass Effect 3, but they aren't terrible. The UI is pretty bad and has a lot of inconsistencies that hopefully get fixed, for example marking items for deconstruction moves the cursor to the next item in the normal bag, but in the vendor screens or your contaminated bag marking does not move the cursor. Holding a key/button for most actions has gotten annoying, like with looting: taking one item is a button press and looting all is a button hold (different buttons in each case, mind you). Fast traveling is reduced to two locations in the whole starting area, which makes running to the DZ kind of a pain if you go back to your main base.
TL;DR: If the game is cleaned up a bit and the rest of the content is good (I think it will be), then I think The Division will be worth full price.