I have seen the QTKitServer in an unresponsive state too. Filter on 'QTKit' or 'Quicktime' in the 'All messages' section of Console if you want to troubleshoot that specifically. It seems harmless to me, I haven't seen the slowness when it was marked not-responding.
Have you considered that Sophos autoupdate using 900MB of RAM is perhaps a little excessive?
SophosScan is also running (as root).
'Window Magnet', that doesn't seem like a default app?
Looking at your What%27s+Running+and+How+much+is+used.jpg, the data read & written is rather high, has this been running a while or has Time Machine been backing up the entire system? Perhaps Sophos is scanning everything?
I realize you are probably trying to get this to run all the apps you need, however some just seem to be incompatible with 10.9, if you post an EtreCheck report (in a new thread please, link it from here) we will try our best to help.
petermac87, do those PID's look high to you? Some are around 11100, it may be nomal if the Mac has been up for days.
See if you have any 'Throttling' blah 'Respawning' blah, messages in the 'All messages' too.