immediately after upgrading, i now have daily issue with the entire system freezing. no beach balls, the UI becomes totally frozen and unresponsive, such that the first few times, i bit the bullet after a few minutes and did a hard reset. but as it happens, i've discovered that it will resume, and execute all of my inputs in a sudden flurry, sometimes after up to 5 minutes!
this is not a once off occurrence either. it happens DAILY, sometimes multiple times. i've now gotten in the habit of restarting every day since the frequency of freezes seems to increase the longer the system is on. i thought those days were long behind me.
i've verified the disk, repaired permissions, done SMC reset, all to no avail. i'd gone to the extra effort of making sure i did a fresh install of mavericks rather than an upgrade, too, and i did not restore from any backups.
i like what they were trying to do with mavericks, i really do. and i'm willing to accept a few quirks on initial release, but this has been really disappointing. its been over a month since release, and it is suffering from severe instability.