People who is using it are very happy with it. Personally I would like to see dyno graph with air fuel mixture in it.
Piggy bag system like Fi2000 continuously altering signal from oxidant sensor to the ECU. So your ECU is still controlling injector dwell and timing but with "false" signal from Fi2000.
This could be very cool system to run, but it also could lead to permanent engine damage.
Like I said earlier I would like to see the dyno graph and I want to know if the system have any way to control timing advance.