I just replaced the fuel pump in my '05 3.0L. I see absolutely no reason to replace the entire assembly, you can replace the pump separately. I was sitting at a traffic light at the exit from Sam's Club, the light turned green and I stepped on the gas, the engine stalled as if it was sucking air. I had come from the gas station in the last 25 miles so the tank was filled. I pulled the old pump and did a continuity test, it was open. The new pump had resistance. It could have taken as little as 30 minutes to replace the fuel pump, but I had trouble with the seal -- which is actually easy to not have trouble with -- that slowed me down. I would not recommend changing the fuel pump on a full tank of gas, but sometimes you can't always get what you want.

Personally, in all of my years owning cars, this is the second fuel pump that failed me. I would not bother stocking a pump for the next time.