I honestly don't know about longevity. All I know is that recently I printed 200 shots at Futureshop, Costco and The Lounge (my pro photofinisher). The results are as follows:
1. Stacked, Costco stack is the lowest, with Futureshop second and The Lounge being the thickest by a small margin over Futureshop (but FAR thicker stack than Costco.
2. Colour rendition, my pics at Costco are all washed out. Similar colour rendition between Futureshop and The Lounge with Futureshop being more saturated. This is after explicitly instructing all of them to NOT do colour/exposure correction. I compare the final prints with several prints I've made from home (calibrated monitor and printer). The Lounge is dead-on with my reference print.
3. Price, well, Futureshop is overly expensive, Costco (Markham location) is the same price as The Lounge but considering addendum 1 and 2, I'll stay away from Costco.
Funny you should mention Fuji Paper at Costco because my latest print at Markham Costco doesn't even show what brand of photo paper they use. Maybe they are one of the deliquent Costcos? Regardless, they currently are replacing all their machine and tearing down the entire photo finishing area at Costco Markham.