Great eval! If you are comparing search strategies, ultra mode is likely superior. Would love to see a follow-up evaluating that.
Ultra can fan out parallel investigators, run adversarial review at defined checkpoints, and do a bunch of other smart stuff to avoid getting stuck in a local optimum.
Generally as the OP notes, /goal works better for single-track investigations or small scale scatter/gather.
I think ultra mode needs to be more clearly documented (or perhaps cautioned against!). Most devs - myself included - who saw “ultra” mode figured that it’s just a magic bullet that makes the model work harder and achieve better results. But, for many tasks, ultra mode is possibly worse and certainly more expensive.