Kat: I too am a Nikon & a Mac junkie.. much like driving my VX, I refuse to lay my hands on the pc that's in my living room.. lol.. unless it needs tech support because it's dying.. or whatever else issues pc users have.. I find that running Chrome browser seems to be the best.. I can't stand slow safari.. even firefox makes me nuts.. too slow.. if you're finding across the board that websites in general are ALL seeming to have issues, reboot (shut off /unplug-wait 30 seconds plug back in) routers & modems or whatever web access you have. For instance, I find about once a month chrome on my mac starts slowing way down, pages won't load for what seems like eternity.. error logs, all the bs.. I reboot modem & router that's wired to the PC (Im wireless on my MacBook) and it's triple speed and runs great on any website..
As far as websites for hosting photo's only.. I use a few, I am a freelance photographer, and I tend to use caution when posting gallery worthy photo's just anywhere.. so I guess it depends on really what you're looking for. Large amounts of storage space? displaying a few great pic's? selling them? all of the above? I use photobucket for daily snap shots not worth $$.. cafepress for selling.. copyright protected..