It sounds like the salesmanship is souring you on the tires, which doesn't seem fair to the tires. The other brand wouldn't have been any different. Big soft tires are supposed to be run at low pressure to give you a soft ride. That's how they work and what they're for. But because of that they'll also give you vague handling. The carcass distends a lot, not just up and down but also side to side and turning. Think of it like shoes. You just bought Crocs.