in the world of diesel's, can you ever have too much fuel supply? The 150 has filters this one doesn't. with this one you can use your factory canister, or do like i did and buy a fleetguard filter head and 10 micron filter and make your own fuel system.
Yes, it will return a lot of fuel that you did not use.
The immediate issue I see is that you will introduce more air into the fuel in the tank (foam) when you return a large amount. On a puller, it is not a big deal as you are not returning as much fuel as a street truck.