I think that the bonus, while small, since it applies to an entire system and not just one planet, is really more than it seems. (In stock, all players HAD was the per-system happiness effect, so they were in a sense spoiled!
) However, since you don't get a stacking effect from building multiple UPC's, I'd think that it might help to do something different with the UPC's - maybe make 5 levels of them, starting at level 1 of Applied Political Science, or increase their effect to 2/3/5, or something like that.