The series boasts top-notch animation for a TV-series, even by Japanese standards (and I've watched a lot of anime), and the dialogue is neither stale nor repetitive. Even though each episode deals with a card capture, the writers managed to make each day new and interesting rather than a repeated "Oh, lookie, Sakura's going to capture another card". In fact, some episodes feature a capture as just a brief side-plot with the focus on Sakura's relationships, worries, or other points of pre-adolescence. This is everthing "Sailor Moon" should have been, but wasn't.
"Sailor Moon" was a cute show, but really one-dimensional in a way only six-year olds could really enjoy. I admit, "Sailor Moon" is cute and I watched it when I was little, but it doesn't contain the depth of character, plot, and animation as "Cardcaptor Sakura". What makes Sakura so endearing is that she's quite capable, and even when she screws up she fights it out. One of the most annoying habits of "Sailor Moon" is how the lead character is saved or at least aided practically every time by the dashing male lead, Tuxedo Kamen ("Tuxedo Mask", in the US dub). Sakura proves that a girl can kick butt thoroughly.
Also, in Sakura's world, people are not perfect or one-dimensional. Li Shaorun can be a brat (and eventually evolves to crushing on Sakura as the series progresses), but he's that way because of his background. He's been ingrained by his family to capture cards, and at first he sees Sakura as an amateur rival who he doesn't need (he actually feels threatened by her presence in the beginning). Tomoyo, an amateur film freak, drags her videocamera everywhere to film Sakura's captures, and has a few stints of her own. Even Kero, with his sharp mouth and love of video games, and Sakura's older brother, a true pain in the butt (in an endearing and entirely lifelife way), makes the series all the more realistic and worthwhile. Unlike "Sailor Moon", here there are no "throwaway" characters, even Sakura's band of clueless schoolfriends. Nobody here is one-dimensional.
This series is a definite recommendation to everyone, but my advice is to buy the DVD volumes, which you can find on Amazon.com. Unfortunately, the American dub doesn't even include the first eight episodes, so you don't even see Sakura accidently freeing the cards!! Some of the DVDs have the option of subbed or dubbed English, I think, but they're totally worthwhile. As of this printing, there are five volumes (with about eight episodes on each) made available in this country, with more coming. I HIGHLY recommend them.