Taz of Tasmania actually bugged me, but I loved Tiny Toons. It was great, but I think they ultimate Looney Toons for today is actually Animaniacs. That show could do no wrong, and they even launched one of the best cartoons made in the US: Pinky And the Brain....But then that lead to Pinky, Elmyra, and the Brain, but let's not talk about that.
And I agree that Batman Beyond is an example of an update gone right. I still wish they'd continue that over The Batman. (Note he is Batman! Not THE Batman! Ugh!). That show was great, and I could think of only one lame episode. And Will Friedel was amazing in it.
My rule for new shows: after three episodes, put on the judge's gown, but not an episode before.
The Loonatics is a little shocking, and a little cheesy sounding, as its pitch sounds weak, but it got approved by the same guys who said "Da Boom Crew? Sign me up!" So we should trust their wisdom...