i may be baised as well, but in comparing the p5 to the 3, i'd probably go with the p5 for exterior styling. the 3 has the bigger engine which i was hoping to find when i bought my car, but eh. interior design-wise, i like the look of the 3...also the 3 has little things that just seem to be more convenient (like the cup holders in the door). stupid little things like that.
if i were to get a 3, i think the sedan looks better than the 5 door, where as the p5 for the protege's. but that's just my opinion