Honestly, I'm not sure there's much of a difference for me between Nemesis and Undiscovered Country. Nemesis is very obviously flawed, but significantly under-rated. The Undiscovered Country is VASTLY over-rated (cheap and messy), at least relative to the fan praise it receives. Due to this, there isn't much separation between the two from my vantage point. YMMV of course. Just one man's admittedly unpopular opinion!