The only logical choices you have listed are at the bottom of your list. The Pugsley is not versatile enough, it's clumsy-looking, and will give both your peers and professors, the wrong impression of you....Well, let's just say, that you don't want them to have that impression of you!
You don't want the Cannondale, because it's not ultilitarian enough. The Spearfish is a fully suspended MTB. C'mon, seriously! That's just far too impractical! You would actually entertain the idea of commuting with a FS MTB. Where do you go the school? ..On Mt. Everest or something! Ok, let's put it this way....Nope!
The Roper I absolutely love! ...However, I'd own the Ogre in Derore XT/105, some disc brakes, and a set of Panaracer Rampages!
Good Luck in grad school!
Happy Trails, friend...
- Slim
PS.
That's funny! My initial thoughts were exactly the same as Matimeo's...
You actually sound as though, you've graduated and have landed that first job in your desired profession.