Zork II incorporates my favorite puzzles from MIT Zork: the palantirs, the tea room, the round room, the robot, the volcano, the glacier room. The dragon (a callback to Adventure) was a fun challenge, and the two or three NPCs made the game quite fun. I enjoyed watching the wizard travel around zapping me.
I prefer Zork I's treasure drop off system, however. It was annoying having a huge pile of treasure, not knowing what to do with it.
I used a walkthrough on a few places (especially the oddly-angled room), because I wanted to see the whole game. Having completed MIT Zork before made some of the hardest puzzles trivial.