Thanks Lurker, but we have been through the bit about the best record before. Just beating out another team isn't really a great differential. But when a team is close to or above 70 games, it's not just a little better, it's a lot better!
So you may want to discount what Dallas has done, but based on the past, that would appear to be a mistake.
It's actually more important to know how the top teams do against other top teams. It's one thing to beat up on the Celtics or the Sixers, quite another to routinely beat a Cleveland or a Washington or a Utah.
Head to head between teams used to be a good indicator, but teams don't play each other enough during the regular season to strategize for it. Back in the old days when teams played each other 5-6 times during the regular season, and there were fewer playoff spots, teams worked much harder on game planning to beat specific opponents.
The NBA has gotten too big for that, and it's lost something as a result. I grew up watching the Sixers and Celts battle it out every year. And the rivalry was very entertaining. You could see them get up for every game just to see what was up. They would work very hard on trying to come up with a successful game plan in the reg. season, and this would carry over into the playoffs.
Now, more than half the teams in the league get into the playoffs, so regular season play has lost some of it's significance, and there are fewer teams who are real contenders and many more who are pretenders.
Dallas just bettered the Spurs last year, and it was a very close series. It would be reasonable to expect if these teams meet again, it will be very similar to last year, with the outcome uncertain. I might argue that Dallas is better, but not by enough to make a series between the two a lock.
I thought Dallas was actually better than Miami last year, but they choked. Miami deserves some credit for that!