I saw the Americanized Grudge in the theaters and it remains one of those movies that I have a difficult time watching because I get too creeped out. Pale freaky asian boys + contorted black haired women = a creeptastic experience for me. I had delayed watching Ju-On cause I didn't think I'd be able to sleep afterwards.
Well, I finally sucked it up and rented it from Netflix. Comparing The Grudge with Ju-On, it was evident that bits and pieces of the Japanese story were used to make a solid story line in the American version. Ju-On, on the other hand, follows multiple story lines, treated as chapters, with the creepy woman/child being the common thread to tie them all together. I wish I would have seen this version first actually, because it threw me for a loop at first. (I was essentially expecting the same exact story and structure, but in Japanese...kinda how the Ringu/The Ring played out.) Not that this was a bad thing. In fact, I have a theory that The Grudge 2 is based on another chapter in Ju-On, so it'll be interesting to see how that goes.
Now creepy-wise... I still felt this movie was just as creepy as its Americanized version. I mean, hell...the whole pale, wide-eyed, semi-naked boy popping up everywhere was just unsettling enough. Now add in the crawling woman showing up in the bathroom, bedroom, in the freaking bed (that's a safety zone for crying out loud!) and I think I may have clawed up my husband.
Ultimately, what I like about this film is it manages to be creepy in either language. There's not a whole lost in translation effect, like in Kairo.