I have no info on the allisport chip but the general consensus on this and other forums is the way to go is with a remap by either mike from dynachip or remap from td5 alive i had my disco remapped by mike from dynachip totally transforms the driving experience better throttle response more low torque better pulling power and better fuel figures highly reccomended
Just did mine from a guy in Portugal (Td5 inside) just a week ago. He sent me via post a used and flashable ECU with a new map in it to sustitute my 2001 not programmable one, and I can only say this, or any similar one, is the only way to go !!
What a difference.. of course I had verified all engine components are ok, and got a td5inside type of larger intercooler installed before.