It's a case by case basis with me. I think the Flash works much better as a legacy with a full Flash family. But then we get two Supermen, three Wonder Girls, 6-8 Earth related GLs before we even get to Alan and his kids, etc and it all gets to be too crowded.
Donna is my favorite Wonder Girl just on the basis of being so good in the Perez NTT issues, plus she's connected to Dick. She's a mess the rest of the time. But while I used to be neutral on the Kapatelis women, I like them more and more on re-reads. Like Gaius said, Vanessa in that run is a better written character even without being a Wonder Girl than the actual Wonder Girls