The only version I watched was TVB's version. Really enjoyed that one. I thought the majority of the cast was great, including the female cast. I liked how the females had their own storylines that contributed to the four's character development. Also, I have a weak spot for Kenneth-Selena pairing. =]
I'm really watching this as a 'Romance of the Four Constables' type of thing. If you expect it to be anything else you'll be extremely disappointed. There are a lot of flaws and inconsistencies that don't make sense, and the storyline seems choppy. The females can get annoying (i.e. the princess...and Gui Gui being all weird and overly clingy), but Janine Chang is really enjoyable. I looooove William Chan in here; he's so spunky and adorable. I feel bad for how devoted he is to his princess, but I enjoy every scene he's in.
Also, no drama is free from females backstabbing each other. -______- They somehow managed to sneak that one in too. Really annoying.
Other thoughts:
Mickey He's character freaks the heck out of me, and I don't know if this means he's doing a good job. It's really strange watching a man with white hair and bad eyeshadow/blush crazily mourning his dead love for like five minutes with background music. So draggy.