i use a navi too with the BC2 ST and sensitivities of 50 & 75.
its OK and i'm much better with my aim than using the dual shock but... turning/camera look is not very good. i really want to get a config nailed down before UC3 releases so i'll start testing out new settings. unfortunately i'm not much of an expert setting up the XIM3.
i searched too, but didn't see the crisis ST config you mention, can you link to it?