I grew up with the original series, but...
Okay, as with a lot of people, I grew up with the original series, but I find myself liking the 2k3 version more and more. Don't get me wrong, the 80s series was great and started me off with the Turtles, but as a comic book reader, I tend to side with the comics on a lot of adaptions.
So after reading the first 10 issues of TMNT, I realized that the 2k3 series was so much closer to the original comics and this is part of my decision.
Now...I'm not saying there should be a 100% accurate adaption, but it should have the same feeling as the original comics and this is why I think so many 80s fans dislike this series: it doesn't have the same feeling as the 80s series, but is much closer to the comics and characterizes the Turtles the same way.
As far as Shredder goes...it's awkward, true, but it's not the only change I've seen from comic to cartoon and I think it's an acceptable one. Others have been things like Montana becoming The Shocker in Spectacular Spider-Man or the creation of The Joker's sidekick, Harley Quinn in Batman: The Animated Series. It's artistic license that I think works to an extent. Doesn't really bother me all that much.
For the people who don't really like the 2k3, the 80s series is out of DVD and the creation of the 2k3 certainly doesn't detract from it. I, for one, will rewatch both.
________
Brought to you in glorious Pool-o-Vision™.