When playing against comparable powerful teams, home-court is very important. Given, it shouldn't be acquired at the expense of our health and preparation entering the playoffs. But it's certainly important.
Historically, at least during the last 15 years or so, the team with Home-Court advantage in the Finals have won the championship the great majority of the time. These finding aren't as evident when you look round for round during the playoffs. The reason for this is, that quite often the best teams might not possess home-court advantage during the early rounds (sometimes because of injuries during the season or teams that pace themselves, like the Spurs, or simply teams that suddenly starting playing really well during the later half the season, while teams with early season success might be struggling). But once we get to the later rounds and the finals, the weak teams are usually weeded out and the best teams usually remain... and it's during these rounds that Home-Court becomes a huge factor.