I don't think it's possible to see every potential problem that may occur with any product. I was once a factory auto tech and we were always fixing something that was unforeseen. I've found WA products to work very well right out of the box, and they've always helped post haste with quirks, once at 10:21pm on a Sunday.
And PHP is, well, PHP. Trying to remember the humorous quip about it that my engineering friend who was at Google said but I just can't find it in the nooks and crannies... I really should learn the language so I can stop harassing these guys.
Btw, WA dudes, my CMS install went great! Used this thread's subject once, too... rad!