POLL: Keep stock 550D fans or upgrade to AF/SP fans?

Quick poll here everybody. I have a Corsair Obsidian 550D case and a Corsair H100i Hydro series cooler. The case comes stock with 2 front intake fans (120mm) and 1 rear exhaust fan (120mm). I'm wondering if the stock Corsair fans (for the case and radiator) are good enough or if it's worth it to upgrade them to AF/SP Corsair fans? I'm less worried about physical appearance, as the 550D does not have a window, and more concerned with raw performance.



So....



Who would leave the stock fans?



and



Who would upgrade to AF/SP fans?



EDIT: I guess this could have been posted in the cases section, but it could also be posted here...