Better, for sure. A healthy Andre Drummond, Blake Griffin, and others return, and they added Derrick Rose- former MVP, finally healthy after a long ordeal-currently slotted as the backup point guard, I expect that will change as the season goes on. He's still got it.
Klay Thompson will miss most of the season due to injury. That's a huge blow to the team, as Klay is part of the core, with Steph and Draymond. They return healthy, but as we saw in the finals...they are vulnerable. In fact, most people who follow the NBA believe this off-season was so wild because teams feel like they have a shot to win the title for the first time in a long while- the Warriors have been unbeatable over the past several years, and only lost last year due to losing two of their key players to injury. They still have Steph Curry, and they still have Draymond. But they are not unbeatable this year.
The new players they brought in are a little baffling. They got D'Angelo Russell from the Nets in exchange for Durant. That's bizarre, he's a starting caliber point guard when they already have the best one in the game in Steph. They plan to make Russell play shooting guard, at least until Klay returns. Willie Cauley-Stein is their new starting center, after losing DeMarcus Cousins to free agency and Damian Jones to trade. They will still make the playoffs, that's for sure. But it's not going to be as happy a season in their new arena as the previous few have been.
The Heat are a team that got both better and worse. (lateral) They got Jimmy Butler via sign and trade, but they lost their best center (Hassan Whiteside) even though they refused to actually play him when it mattered. The biggest loss, though, is Dwyane Wade, who retired. If Jimmy Butler can stay healthy, he can probably will them into the playoffs all by himself.
The Kings barely missed the playoffs last year, and should be better this year. De'Aaron Fox has become one of the point guards of the future...and one of the biggest improvements I've ever seen from a player year to year. If he can continue that trajectory, he will be an all-star someday, and the Kings may play in the playoffs for the first time since 2009 because of him and his teammates' continued growth.
The champion...well that's tough to predict. The Warriors have been the odds-on pick to win for the past several years, and would have won last year if Kevin Durant and Klay Thompson didn't get injured. I don't think the Warriors will win it all this year, although Klay is expected back before the end of the season. I think it will be Rockets over Bucks.