the diff is between eSupport and SupportSuite is just that SupportSuite has the LiveChat module built in but you can upgrade to this later if you ever wanted, so I just got the eSupport Suite
There are a few issues with LoginShare under certain situations...however there is a 3rd party solution is available to fix it (but it costs some $). See this thread for details:
http://forums.kayako.com/showthread.php?t=6259