von shill v taelor really comes down to personal preference and opponent, strategy & schemes i think you cant go wrong with either.
eg against kirai you would want taelor for the magical weapon, but anything else you could argue either since v. shill is harder to kill can get rid of corpse counters and make constructs slow whereas taelor has higher damage output, the positive damage trigger on constructs and ignores armour (i know v. shill ignores armour on his knife but its better to use his gun).
v. shill is also a lot faster so can get to treasure, evidence markers etc very quickly (especially if a student give him fast, thats 20" of the board turn 1). and finally he give the librarian slow to die when he is close, so your df3 6wd model isnt quite so easy to kill.