Serie A is shit. A well oiled Napoli, with two players in red hot form won't change that.
It's entertaining league. But no elite teams in it.
If Napoli get drawn against a top side and take them out in CL... different story... then they officially arrive as a top tier team. I'm rooting for them, but they're still somewhat unproven against top teams.
Let's not forget that Napoli was beaten at home by Xavi's Barca last year.