But the Heat's days of being juggernauts ended once James decided to head home.
This Heat team has legitimate flaws and question marks that could ultimately hold them back from having the type of great season that remains possible.
Let's take an in-depth look at those flaws and what they mean to Miami.
Miami's spacing takes a sizable hit with James' departure. The attention he commanded and his versatile skill set opened up the floor for the Heat and the team was often to able to leave possessions having taken the best possible shot.
Unfortunately for Miami, they don't have that luxury anymore and there's reason for concern.
Miami's prized free-agent pick up Luol Deng is a very good player, but he can't shoot the ball (30.2 3P% in 2013-14) or space the floor, which presents problems. His deficiencies in those areas are especially troublesome when considering Dwyane Wade is weak in those facets of the game as well.
In a league that values the three-point shot more than ever, Miami's two starting wing players aren't threats from outside.
Now, the Heat still have a stretch-four in Josh McRoberts and an outstanding small-ball five in Bosh, so they will have spacing advantages from positions that plenty of other teams don't.
But this isn't going to be the dynamic and, at times, borderline unstoppable offense that Miami ran for the past few years, which will put significant pressure on this team to excel on the defensive end.
The Heat ranked dead last in rebounds per game in each of the past two seasons. However, Miami was still able to win at an extremely high level because on a nightly basis they were often better than their opponent in just about every other area of the game.
Without James, the Heat don't have those advantages to nearly the same extent anymore.
Considering that, it's easy to say that Miami has to put more of an emphasis on rebounding in 2014-15.
But the problem for the Heat is that they didn't sign very many skilled rebounders this summer.
Deng (5.7 RPG in 2013-14) averaged 1.2 fewer rebounds per game than James (6.9) did last season. McRoberts, who will start at power forward for Miami, averaged just 4.8 per game with Charlotte this past year.
Miami is likely going to drop a game here and there simply as a result of their work on the glass. And with their roster for the 2014-15 season just about set, there's really not much they can do at this point to prevent that without a system overhaul.
Pat Riley did about as good a job as one could possibly expect him to do in the wake of James' departure from a free-agent standpoint. Re-signing Bosh and Wade while also bringing in Deng will make this team competitive at the very least.
But without James, the Heat weren't able to convince proven veterans, such as Shawn Marion, to sign for cheap.
Instead, Miami had to take fliers on guys such as Reggie Williams, Shawne Williams, Shannon Brown and Danny Granger (who agreed with Heat before LeBron decided to leave).
Reggie Williams appeared in just three NBA games last season. Shawne Williams appeared in 36. Brown appeared in 29. Granger appeared in 41 and his best days of basketball are long behind him.
The Heat will end up on relying at least a couple of these guys and that's dangerous.
There's certainly upside. Reggie Williams (37.1 career 3P%) can help with spacing. Shawne Williams could fill in as a decent stretch 4 if he shoots better than he did last year (32.6 3P%). Brown is just two years removed from averaging north of 10 points per game with the Phoenix Suns. Granger is a former all-star (2009) and there's a chance for a slight bounce back from him.
But none of that is certain. These guys are question marks and that's something the Heat have to be worried about entering the upcoming season.