Errant Hothy
Hypermediocrity
Because McCaffrey is the better athlete, had a better season and has more upside since he's only played the position one yr.
I'm not sold on the difference in their athletic ability being as great as it is currently hyped to be. The "better season" needs context, McCaffrey was the first option for Rice; Whittington was the third or fourth option and still produced as many TDs as McCaffrey on 12 yards per catch average (14 for McCaffrey). Whittington is by far the more polished route runner.
Upside is never guaranteed to be meet.
Both are projected to be Day 3 guys. Personally I'd prefer Whittington over McCaffery