Samurott is unimpressive compared to the other water types in the game, same with Emboar.
I chose Snivy and love it and will probably keep using, unless I switch it out for Cottonee.
(I don't think Serperior is outclassed by Lilligant (Sp. Sweeper Grass Type?) and Whimsicott (Whimsi doesn't get Coil)