I agree with that however I do think they're improving. Granted their record against winning teams still isn't good, but they're still 1st in opponent FG%, 2nd in points allowed, and 4th in point differential. Even if they haven't had the most success against good teams those stats are impressive.
I do agree that their massive weaknesses in post and at the PG spot need to be addressed for them to become a consistent, legitimate championship contender. But it does look like their big 3 are starting to play with more chemistry, and as you said they have the potential to beat any team in the league when they're on. As far as I'm concerned they're far more of a threat to us than Orlando (barring a trade for a star) and if they start playing this well against good teams I'll be worried.