I've read an article about water pieces absorbing the THC, CBD, CBN. Though I questioned it because I've heard that THC is not water soluble.

I think it's a personal preference. Any differences in THC CBD or CBN content is so insignificant that any difference in your high would be negligible. I've never not gotten stoned off of any piece I've used, but I prefer good ol' glass pipes because there's no water or mess!