Yes it is.
It depends on ones preference. K-Pop tends to be more Soul and R&B (not always, but it's still a big influence) and J-Pop tends to be more Pop and Rock. I love them both, but K-Pop has been exploding the last few years and more new and dynamic groups are getting international attention coming out of Korea rather than Japan.
Yeah, it's all about personal taste. K-pop is definitely more popular than J-pop right now. As you probably know, even in Japan, Kara, 2NE1, SNSD are extremely popular. Same deal with K-dramas I think. K-pop presents a fresh, strong, independent image for young women that appeals more than the standard "cute" Japanese one of most girl J-pop groups, so that's one of the reasons why I think K-pop has been more popular lately.
But i'm not sure how long it will last since the music is so banal for me.
Not like Utada Hikaru or Ayumi Hamasaki for example. Then again, recent J-pop has been mediocre IMO. But actually I don't think many J-pop groups are even trying to become famous in the West like K-pop groups are desperately.
K-pop music videos like this one are extremely well produced but, for me, they all look (and sound) the same. Forgettable. The dancing distracts from the bland sound (same can be said for AKB in my opinion
). But overall, J-pop is more versatile and feels a lot more creative in genre. That's probably why it's still the second biggest music industry in the world, it has more to offer.
With K-pop their vocals, dancing, music videos etc are really impressive, but when it comes down to the music, i prefer J-pop.