Trapper vs Hans... well, it's a matter of looking at your intended goal as well as how terrain is looking.
Hans has his free (0) upgrade, can take other upgrades if you so choose, longer range, can apply debuffs, and can ignore armor/incorporeal, ignores bothersome Wp duels such as Horror and Manipulative (take that Doppelganger), ignores terrain markers (suck it Lilith, and shooting through strategy markers is fun), and has +1 Sh. He is incredibly card intensive, though, requiring discards to guarantee triggers or to even apply some of his triggers. The amount of card shedding for only mediocre results is bothersome.
Trapper has From the Shadows, Wk5, 4" push trigger after each shot built into his gun, (0) push out of engagement, attack built into his gun to bypass cover, and Crit Strike in order to one-shot the many, many 6-wound annoying support models that are out there. Between From the Shadows and built-in mobility, the Trapper is far more versatile in most given terrain setups and can double as a scheme runner when needed.
So Hans does more in theory, but Trapper is more mobile and less card hungry.