Yep - many of these Vane pumps will last a long time even as a lift pump, but I think the tendancy is to make things of cheaper materials nowdays to maximize profit. I'm not so sure that they are in it for the long haul anymore. If the pumps are ever run dry for even a short period of time, they will score the inside of the diecast pump chamber and they will no longer produce the suction / pressure that they once would.. I recently took apart a carter vane type pump just to see why it was no longer working. It was placed just on top of the fuel cell. If kept primed, it would work, but as soon as it sat for an hour, it would no longer draw the fuel out of the cell..
So - if they work for you in that type of configuration, that's GREAT - if not, this may be the reason why...