Ok, so here goes. New iMac running OS-X 10.9.5. I found this post while trying to back up my Galaxy Note 3. I believe I had Kies working with Mavericks previously. I have back-ups on my desktop and laptop computers as recently as March and September of 2014, but yesterday I could not get it to work for several different reasons. I tried a number of different versions. The newest, 3.0.1.14124_10 never found the phone by USB, I'm pretty sure, I got so many different errors they have blurred together. I was able to find and download a slightly older version, 3.0.1.14124_6, but had the same problems.
Then I tried the version I believe worked on my laptop, under 10.9 previously, before I updated that to Yosemite, 3.0.1.14032_5. I didn't have the install .dmg file for this version, I just dragged the application file over from my MBP OS-X 10.10 (where it wouldn't connect to my Note) to my iMac 10.9.5. When I launched Kies, it installed its drivers. Installing Kies this way didn't require a restart which the install applications do. This version actually connected to my Note and gave me all the options. Unfortunately, when I tried to backup the Note's contents, it would back up some of them (including Contacts and S Note) but seemed to hang on others (including Call Log, S Health, Alarm and Home Screen), I didn't test them all individually. Call Log I left spinning for over an hour and it never completed.
I also tried an older version I was able to locate on a site in the UK, 3.0.0.13091_3. But I got the dreaded "WMD_AGENT_VERSION" error and, again, was not able to connect to my phone.
I even tried an older version, 1.3.0.12062_4. The installer application wouldn't let me install it, but I was able to unpack the .pkg file and open the application. It would launch, but wouldn't stay running.
I installed all of the Kies applications using the installer applications, where I had them, and unpacking the .pkg file and just dragging the application into the applications folder. It didn't seem to make any difference, but you never know.
I know, TMI, but I wanted to show I really tried Kies before I went to a different option, listed in a following post. Samsung should give us a good way to backup our phones. It should work reliably, easily and it should be included in the cost of the phone. I have been trying to use Kies since at least July 2012 and it has never been easy, even when it has worked.