Bianca's the best draw supporter in format after Juniper and N, no question. If the choice was 50/50 I'd pick Bianca over Cheren any day. That said, it's probably worth testing in whatever deck you use. Odds are Bianca will be the better choice, but Cheren has uses too. After turn 1 really, Bianca just has more uses. It's really only ever not useful if you're winning anyway and have a bunch of cards in hand from prizes + unneeded draws. After you put a basic down, your hand is at 6, at best. You'll only really go down from there, using cards every turn, which makes Bianca live. And while Juniper obviously draws more than Bianca, you can't use more than 4 Juniper.
The way the Skyla/Ultra Ball/Bicycle engine is looking, Hugh isn't going to be worth using...ever, really. But Bianca works with the engine.