Based on photos it appears to me like the Ute and the new Trek Fisher cargo bike have the panniers too far to the rear in relation to the rear axle. Well over half the panniers extend well beyond the rear axle point. Unless you are very careful during loading to minimize the weight in the rear of the panniers. the load will tend to lighten the front end of the bike excessively. I noted this when using shopping panniers on a normal wheelbase length bike prior to getting my Big Dummy.

Both bikes are designed as "Semi Longtail" bikes which compromizes their functionality compared to a xtracycle, Big Dummy or Yuba Mundo when it comes to cargo hauling. Even on my Big Dummy I try to load it with the heavier bags ahead of the rear wheel axle for best handling characteristics.