I disagree: This is a video game and I do not think that 1:1 translations of pen and paper mechanics would make a good video game. The negative points mentioned in the early posts of this thread are not negative for me. For example I like the surfaces and that they are less dominant than in DOS3. Keeping to pure DnD mechanics would drastically restrict creative freedom and personally I'm indifferent to the game being like any abstract rules set - I only care about the game itself.
Aside the fact that this is supposed to be a follow up to beloved seriesm which did adhere to it's source material very closely... 5e rules are pretty freeform, so it would be far less restrictive to stick with them than you think.
