Funny enough Castlevania 1 is my favorite NES game, whereas Metroid 1 is my least favorite at least among those I've completed. They're both clunky, I suppose, but Castlevania's clunkiness feels like it's there very much by design, while Metroid's really feels like a limitation. So much so, that as these series progressed, Metroid got tons of new movement and aiming options (as early as in the next game), whereas Castlevania has generally remained slow-paced and clunky.
Great pick and great points. Castlevania 1 is probably my favorite NES game too.