I liked them! Lots. The measure of an adaptation really shouldn't be "was it perfectly faithful to the source material?", nor should it be "did they leave all your favorite bits in?". Rather, it shouldn't neglect the elements that make the source material beloved (so there should be at least some of the audience's favorite bits) and it should work in a way that captures the tone and intent of the original. So I thought both films worked very well.
I mentioned before that the anime episode where Light weasels Naomi Misora's real name out of her is one of my favorite moments in the entire story, so it seems blasphemous to watch that storyline be tampered with in the first of the live-actions--except that it worked so well. It explored a twist of the Death Note rules that even the source material hadn't addressed--how to make one death affect the deaths of others without violating the rules--so, in providing the audience with extra surprises, I have to give it full marks. It amuses me to think that perhaps the death of Light's girlfriend was included to make the audience less fond of Light by the end. Honey, ifwe don't already have the full measure of Light by the time he offs Raye Penber, no basketload of dead girlfriends is going to make the picture clearer.
Ditto the second film. Oh, they got so much in there. And I was so prepared to be disappointed by the ending--I expected L to defeat Light in this version, given the structure and the time allotted for this film (though they did give us two hours twenty minutes! wow, that delighted me!). And L's fate in the original manga/anime is perfectly structured from early on, so, I thought I was going to be unhappy to see that tampered with. Surprise! Another twist of the rules that wasn't addressed in the original! I remember early on in the anime thinking, "Light, darling, it might not be a bad idea to write in that note of yours, 'Light Yagami: Dies at age 120 years, having lived a long and happy life, in the bed of someone considerably younger than him.'" And after the 23-day rule was learned, it did occur to me that someone in desperate straits might write his own name into the book in that fashion, i.e., "Dies 22 days from now," and then see if he can find a loophole in the next three weeks. So we never got to see that in the original but we saw a version of it here.
And, of course, L does die, so the emotional impact of that is somewhat preserved. While I can't imagine the L of the anime/manga going to his own death in this fashion, I can believe it of this L. I couldn't be as fond of this L, either--most of my love for L is wrapped up in the vulnerability he self-cultivates around Light, and there just wasn't time to develop that. But I'm satisfied. Good job.
I have meta regarding L's death in the original manga/anime, but I think I'll take it over to the death_note comm.