I won't debate Tartakovsky's style much, other than not caring for some of his character designs (I could same the same for the current Clone Wars, too) and the exaggeration of force powers. Some of his action scenes are quite cool. But storywise, the only segment that mattered (besides the introduction of Grievous, which is muddled by the inconsitencies between CW and ROTS versions of the character), was the attack on Coruscant, that leads into ROTS (and was far better than the opening battle/rescue of ROTS that follows it...I'm definately giving Tartakovsky credit there.)
Anyone could argue that parts of Filoni's series don't matter much or don't mesh with the movies. I'd probably agree with them on some points.
Final note: Best thing about the micro-series is that they f-ing killed off Asajj Ventress without dragging that weak ass storyline way past its due. Filoni seems completely unable or unwilling to kill any villains in his series, just good guys. So as a result you have a whole universe of major league scumbags walking around that have somehow scattered into the woodwork prior to ROTS.
The microseries didn't kill Ventress off concretely enough for other folks not to reuse her.
Ventress and Durge were one-note disposable characters. It's only Filoni's Clone Wars use of Ventress that makes her anything to me. Before that she was an EU baddie that as far real canon goes, might as well have never existed Durge was created to replace Jango, then offed immediately...dispite being harder to kill than most life forms (yeah, he came back in a comic book...I don't care). Filler characters until Grievous comes along, only existing because we can't have the Jedi battling movie characters, that would mess with the flow of the next film (Oops...someone forgot to tell Filoni and Company...."I'm twice as powerful as when we last met, Dooku!"....."Ah, yes on Tatooine...no, I mean when were prisoners of those space pirates..."
Also the microseries' battle droid voices were better.