I've been a proponent of Mac and OSX for some time now having been attracted to its simplicity and the 'it just works' way that it operates but since the Mavericks update some things simply don't work. The biggest issue that I have found is that apples newly written USB drivers will not connect to my Arduino, a major PITA when it comes to uploading a new program. The solution is to disable the OSX drivers and install the OEM version which worked for me and seems to work in 95% of cases. Why Apple have decided to move away from the chipsets manufacturers drivers I will never know although I suspect that it may be due to an incompatibility that causes Kernel Panics as I have personally experienced these since moving to the OEM drivers. This is fairly repeatable - hold down the Arduino reset button whilst uploading the program and your machine will likely go into an involuntary and instant reboot. The solution is of course simply not to hold down the reset button but as this is a common hack to get the program to upload you may have to suffer a few missed uploads instead. Not a massive issue, at least I can now communicate with the arduino again.
The most recent issue to hit me as a potential result of Mavericks is that sent email messages seem to disappear into the ether instead of appearing in the sent box as they should. This issue only recently came to light when I needed to find some previous correspondence. For reliability and ease of management I use a hosted exchange server to handle my work emails and OSX Mail as my mail client. What I found was that the last sent message in my sent folder was dated December 2013, the previous correspondence I was looking for was nowhere to be seen. I also checked the exchange OWA browser client but after looking there I also found that there were no recent sent mail messages stored.
After a short call with the exchange tech who advised me to use a client that they supported - namely outlook 2010 - he advised that the issue appeared to be related to the Mavericks update. For some reason the outgoing server had been changed - there were now two exchange outgoing servers in the server list. I changed the outgoing server to the other exchange server listed and sent a test message. Viola! the message was saved in the sent messages folder.
I'm not sure why or how the second outgoing server was added, It's definitely nothing that I have consciously done as the exchange account has not been altered since it was setup in 2010, additionally no one else uses this machine. I can only assume that as the tech suggested it is related to the mavericks update as the last email date roughly coincides with the date that I updated. Of course I am happy to concede that it could be due to some other unrelated reason but knowing that I did not create the second outgoing server makes me wonder how it got there....