Used Kaaz 1.5 with both my b16 & k20, the b16 retained factory steering and was excellent on track, the k20 had no power steering and used for racing was a real handful on the circuit, actually costing me time due to fighting the diff, especially in the tight stuff, you really do need some sort of assist in my opinion. On the road, turning out of a junction at pace was a real mission due to the snatching, TGM have fitted a huge amount of Kazz units and had not found one to be as aggressive as mine.
When the k20 was just a track car, I had the Kaaz fitted, drove it to France for a track day at Abbeville, a really tight circuit, great for go karts, I treated myself to instruction and the guy was a real pita, kept having a dig, 'why are you not listening and doing as I tell you?', I said why don't you show me, so we swapped. At the end of the main straight is a proper tight hairpin, as he tried to corner the steering wheel ripped out of his hands, I didn't need to say anything, my 'tuition' was over shortly after.
The new car has a Cusco fitted, might get to try it next year.