The roly-poly cornering look isn't ideal, but it's certainly fast. A friend of mine that works has worked as an engineer for various IMSA and Indycar teams (and because I supply him with good whisky, has given me pointers on my car setup) has always said "the fastest setup is the softest you can run the car without actually lifting the inside tires." It sounds contrarian, and is definitely not what most drivers (especially in open wheel cars tend to prefer, especially if they've come from karting), but the data doesn't lie in the end.
As a driver you want the car to respond RIGHT NOW, but at the very limit, you have to give up some response for greater overall grip. Me, of course, I just toss it in the corner with a blur of hands and elbows and hope I come out the other side, but that's more a lack of talent than technique
Steve