After a ride on my rallon with the superstar -2 deg head set, the difference is mostly similar to how I felt after I put a -1.5 head set on my old Mojo HD.
Climbing is fine and unaffected, steep downhill is better, but on fast flat’ish trails you really need you to consciously keep your weight over the front otherwise it feels like the front wheel will wash out.
I may try lowering the stem by 10mm, or possibly even a 10mm longer stem to see if that makes it more natural feeling, but at the moment it is more difficult to get enough weight on the front wheel without it feeling a bit unnatural.
Like on my old mojo, I’m not entirely sold on this at the moment, the improvement on steep downhills is significant, but at the moment it is matched by a significant worsening on more mellow trails.