I was underwhelmed by the first one. And the "The End...Or is it?" coda was ridiculous. The Japanese series is far spookier, and much more atmospheric. My girlfriend at the time watched The Grudge and told me "eh, it wasn't that scary". I made her watch Ju-On: The Grudge the next night. She didn't want to turn off the lights afterwards
That said, the sequel looks interesting. And since I'm a sucker for Takako Fuji's portrayal of Kayako, I'm there.