I hate it, so I moved to other software already.
The problem with Synergy is:
on Windows.
Whenever you move the mouse to other screen (1st -> 2nd , or 2nd-> 1st) , the cursor will appear on middle / center of 1st screen like half second.
It's ok, but it's very anoying, and after 2 years already, they did not fix it. So, I moved away and right now I stick with other software already.