I love how the Snoh is getting all this love and hate here, thing is... it is the captain sailing it who makes the difference, one broadside of a 4th rate can really ruin your day in a 6th. A skilled captain, will not come in that situation that often.. (happens though, damn wappen sinking me in one go :D)
Some snow's are outfitted to be extra agile, some are outfitted to be speedy, some are outfitted for straight boardings, learn the captains, learn their tactics and you will come out victorious,
also learn sailing profiles, as it will help you escape if faced by a stronger captain. And sometimes you just lose, just man up say GG and go to your next ship.
Just don't underestimate any ship (how small they might look...) , oh and yes battles can take long vs small ships, they have to fight differently, small guns, small damage, it just takes longer...