OS X 10.9.3 Update causing coreservicesd lag
This is what fixed the problem for me:
- Rebuild the Quicklook cache (in Terminal:
qlmanage -r && qlmanage -r cache) - Rebuild Spotlight index (
sudo mdutil -E /)
I'm not exactly sure which one of those two really caused the problem. You can try them separately.
It takes a while to rebuild both the cache/index, but afterwards Finder worked as expected.