ART: The art style of Hatori Bisco is EXTREMELY unique. Some love it, some hate it; it all depends on your own preferences. Personally, I thought it grew on me a bit as the series progressed. If I can say anything about it, it's very shoujo-esque while being completely original.
CHARACTERS: Wow. Where do I even begin... The series seems like it has the normal stereotypes of shoujo manga, but the way that they're portrayed makes them stand out from the rest: they normally act in an extremely dramatic manner. Plus, the characterisation is extraordinary. While some may find the fact that most of the Host Club members all have angst-ridden pasts (I dunno if Hunny or Mori do, though) rather annoying or repetitive, I found that it balanced the light-hearted feeling of the manga very well, and it gave the characters much more depth (especially the twins). Flashbacks are often used to give an explanation as to why a character acts a certain way, but they do not overpower the actual story itself. As for the leading female character... She is in no way "normal" for shoujo manga. While she does stay rather "helpless" when it comes to physical strength, her attitude is anything but the "damsel in distress" most often seen in shoujo.
PLOT: Well... There really isn't one. The manga's main purpose is just for hilarity, not for serious plotlines. Sure, there's the running threat of the $80,0000 Haruhi owes the Host Club (coughKYOUYAcough) that keeps her in the Host Club and working, but it's only mentioned in passing (such as when Kyouya adds more money to her fine). I guess the series is mostly just about the Host Club itself and the people/relations within it. In short, you don't have to worry about remembering the events of the previous manga. The stories pretty much differ from chapter to chapter without much of a connection between them. The only issues you'd probably have if you skipped from one to three is if there was a majour flashback/revelation in one of the previous chapters or if a majour event occurred that furthered a relationship of some kind. So, while you could potentially read the series at random, you could miss a few references or a bit of characterisation while doing so.
If you want a series full of humourous situations with (eventually) well-developed, pretty characters (and not much else), this is a series for you. However, if you're waiting for a series that has the end pairing completely obvious from the beginning (it may seem like this is true for this series at first, but it's definitely not; blame Haruhi) or one that actually has a plot, then you might want to skip out.