Some people reported that after update something was eating CPU, turned out it was tracker-store. Suggested solution from here: https://askubuntu.com/questions/346211/tracker-store-and-tracker-miner-fs-eating-up-my-cpu-on-every-startup
Ubuntu bug report: https://bugs.launchpad.net/ubuntu/+source/tracker/+bug/911981
Waiting for journal logs.
Someone on forums suggested that:
rm -rf ~/.cache/tracker/
fixes issues with Nautilus lags, might be related.
Another update: doing tracker reset --hard seems to help with all crash/lag issues with tracker.