I guess I’ll go first with my views. 
Superman has always been my favorite comic book character since childhood, so I tend to be a tad over-critical and nitpicky when it comes to him. I have seen many of the Superman cartoons, starting from the Fleischer ones to the Ruby Spears ones and even some of the animated TV movies.
Coming to “Superman: The Animated Series” (S:TAS), for those folks who are unfamiliar with the “Batman: The Animated Series” might find the art style of S:TAS a bit jarring at first. I myself was a bit taken aback by the angular and “boxy” designs of the characters as I hadn’t seen B:TAS. But the style quickly grew on me and now I have come to love and appreciate Bruce Timm’s bold take.
I enjoy the bright colors and the style is great for depicting fight scenes as it endows them with a previously unprecedented dynamism. One can actually feel ever punch thrown! The simplistic approach to the art also prevents any visual distractions as the audience are more engrossed in the proceedings than focusing on the details of the drawings.
The story is written very well and progresses effortlessly from Krypton to Smallville to Metropolis, highlighting the important aspects of each of Superman’s homes. The writers did put nice little spins and additions of their own to the origin story to make it more plausible and give it depth. One example being Brainiac (why do super-intelligent artificial intelligence always turn evil? ;)). Also Superman’s ship not being destroyed when it arrives on Earth is an important plot point which will be explored further in future episodes.
The voice acting and characters are simply brilliant and probably the best thing about the series!!
Superman: The writers have given him limited powers and strength. When trying to accomplish very difficult tasks, he does struggle and has to really exert himself, unlike the old comics where he could hold up a million ton tanker on his pinky! Also he does suffer some sort of impact when powerful weapons and explosives are used. This makes him more believable and also eliminates the need for writers to have Kryptonite or insanely powerful aliens in every episode in order to create conflict.
Clark Kent: He is no longer the comedic, cumbersome Chaplin-esque fool who only pretends to be a journalist. This Clark actually is a good journalist and displays his intelligence as well. He uses his resources more instead of just relying on super hearing. He looks and behaves like any normal human being and easily blends into Metropolis rather than sticking out like a sore thumb.
Lois Lane: A woman with gumption! She takes her career dead seriously, and will jump into any dangerous situation headlong just so that she is the first to get the story. It may sound stupid but she does it so well that to the viewer it seems more brave than foolhardy. Also it is necessary for her to be like that as this gives Superman a reason to rescue her, the basis of their relationship. She did remind me a lot of Margot Kidder’s take on the character, except that she isn’t overly swooned by Superman like Margot was. And I love her banter with Clark!
Jimmy Olsen: He has been updated very well to fit the attitude of teenagers of the present times. In the old versions he was a one-dimensional city bumpkin.
Lex Luthor: Last but not least, my favorite character in the whole series!!! This is how Luthor should be done. A businessman to the core, weighing everything in profit and loss. He is incredibly intelligent as well. But it really is the brilliant voice of Clancy Brown (Mark and Liam you probably know him better as Captain Hadley from “The Shawshank Redemption”) that elevates this character to another level completely.
