Spalletti has been working with Napoli for quite a long time so that they finally managed to win Serie A and this is different from Conte who has just coached Napoli but he was able to make a very significant difference to Napoli's performance.
In terms of strength, Napoli is now very good but they must be able to maintain their consistency, at the beginning of the season like this we have not been able to measure the true strength of the team, let alone maintaining consistency, of course it is not easy.
What Conte has done with Napoli is impressive, but it's important to keep in mind that we are only at the beginning of the season. Consistency will be key in determining the true strength of the team. Like Spalletti, Conte's impact has been immediate and significant, likely due to his champion mentality that he instills in his players. However, maintaining this level of performance throughout the season and indeed, in the midst of competing in smaller competitions as well as the UCL and the UEL, will be the real test. If Naples is able to do so, there's a good chance of them becoming a major threat this season, possibly even taking the lead in Serie A and winning the Scudetto title.
Every single point matters in football so despite the fact that we are still at the early stages of the league, just like you rightly said, it is impressive seeing how great Napoli have become under the management of Antonio Conte. What he is doing in Napoli is far greater than what he did with his most recent club Tottenham and I have the confidence that he will finish this season strong. To be honest, I did not see this kind of performance coming but he made it possible even with no much sophisticated players. We need to give him the credit because Napoli has suddenly become a kind of consistent which is a good thing.