Lastly check with all the manufactures of you critical software that they have 10.9 version out yet. A lot of programs aren't ready for 10.9. Lastly pay attention to one new Security privacy section in System Preferences ->Security, Privacy mini-tab. There is now an allow check boxes for some programs that needs pay attention too.
Lastly one tip I use (and it still works) is getting Airdrop to work on your 2008 Mac (if it has a wireless N Airport card). Just fire up Terminal and put in the code:
There is definitely issues with 10.9 and this computer: freezes on startup, freezes on shutdown , etc.
Here are two things that temporarily address the freezing issues:
1. Reset SMC. This is really important
2. And then do MULTIPLE resets of PRAM in a row. I do three and it seems to do the trick.
If you are unfamiliar with doing them, just use 'the google' and there are a lot of entries.
Let me know if that help you as it has helped me.
P.S. And when it freezes again, you'll need to do the SMC/PRAM reset again. Yes, its a pain in the zzz but it works for while.