Not to mention the Bimbettes, despite their official name, were strongly implied to have been virgins (due to Gaston completely ignoring them for Belle, and likewise due to their being obsessed with Gaston they're not focusing on, much less copulating with any of the other men in the village), while the Balcony Harem Girls are most likely not virgins (aside from their name, their manager explicitly referred to them as a "Harem" in the opening song, and considering "harem" basically means brothels or whorehouses in the Middle East, you can pretty much guess what that implies about them.).
And yeah, you're right, the triplets were definitely nicer (if I recall correctly, the Harem Girls were sarcastic with Aladdin [who wasn't even intending to see them, but just trying to find a hiding spot from the guards since he was on the lam for stealing bread], and deliberately knocked him off their building). I don't recall them actually mocking Belle's father, and they seemed shocked that Belle would not accept Gaston rather than actually being antagonistic of her for being Gaston's focus (which is saying a lot, especially when she's effectively a rival to them for Gaston's attention), and even when they effectively supported Gaston's plan to persecute Maurice, I don't recall them actually mocking Maurice or laughing at him when he entered the tavern raving about the Beast holding Belle captive. Probably the closest they've ever gotten to doing something like the harem girls is when they squirted LeFou, and it was obvious that wasn't even intentional (they didn't realize he was nearby, and were pretty obviously distracted by Gaston). They were definitely a lot nicer than Beauty's sisters in the original tale.
BTW, is it just me, or do the triplets, from the way the scene was taken, look like they're slightly intimidated by the Harem girls?
Well, the word they're derived from, "bimbo," does have lack of intellect as a partial definition (although I've heard that it also means that they "use their body to get what they want."). They did have some degree of cleverness though, or at least Laura (the amber dressed one) in supplementary materials such as the marvel comics.
While I may not necessarily like the triplets for their effectively being designed in a way similar to the Female Anime Stereotype (you know, how girls are generally depicted in animes such as Love Hina, the Fiorello Fangirls in Princess v. Princess), I do place a lot more trust in them than in Belle right now, not because they are more beautiful than her, but because the little we know of their characters suggests they are loyal to males (ie, they won't become man-haters) and they may have Christian morality (the latter's mainly because the village is implied to be fairly devout in Christianity, with the exception of Belle). Having gone through a fairly terrible College experience where many times Christianity, if it is brought up, is usually bashed (I was raised Catholic), not to mention bashing my gender (male) and pushing leftism that directly attacks religion and traditional morality, Belle's actions on close examination are closer to those professors and students than they are to someone I would respect (plus the movie pushed the same lie that most women were uneducated and illiterate until the 1960s). The fact that Beauty and the Beast took place nearing the events of the French Revolution doesn't help matters, either (never really understood why they didn't just set it near the time of the original tale (which is the late 1400s at the latest) instead of the late 18th century, which is what Keane confirmed, and why did it have to be nearing the end of the 18th century when any century would work [save for mid-to-late 19th century and beyond]).