I'm a base, and I prefer if my flyer has defiances over vengeance. Mostly because the def are a lot more sturdy and won't bend say if the flyer was to lean back and doesn't squeeze her entire body/feet, so it's easier to keep her steady. Also the ven tends to get bigger, and thus more loose on the foot, which in turn makes you not able to grip the foot properly. And since it's not really any shoe there, mostly just fabric, it can get a bit hard to feel like you've got a real grip. Even if the def were to be too big, the shoe itself would still make it feel like you got a proper grip and can adjust your flyers feet. I've got def myself and I prefer them to ven in all and everything, jumps, tumbling, I've got problems with my knees and ankles myself and ven just doesn't cut it for me. And it's not like they're way heavier either.