A little randomness for my Mac-flavored peeps. I updated Spunky (my MacBook Air) to the 10.10.3 version late last week and noticed that I’d been having REALLY slow performance when I went to upload/download stuff from my Downloads folder. After a few minutes of digging this morning, I found the answer, and it seems to have worked in my case. It appears to be a cache issue with Finder.
I started with the easy (duh) and did the reboot into Safe mode by holding down the shift key. It took a LONG time for it to reboot doing that (over a minute, slow for my machine) and then when I rebooted again into normal mode, voila, so far, my issue seems to be resolved (so far).
Hope this helps anyone going through what I did. There are more detailed fixes you can try in that article if the Safe reboot doesn’t work for you. And here’s another article with more/similar info as well.