Remotely accessing OSX Lion from Windows in a sane manner
Solution 1:
Install Vine server on the Mac side and play around with the VNC settings. I would also try a different VNC client on the Windows side.
I've had luck with RealVNC Viewer and found that changing the encoding and color level in RealVNC helps to speed things up.
Solution 2:
I had the same problem with macmini lion server - this sorted it after a reboot https://discussions.apple.com/thread/3289794 .
It's seems a bizarre set of instructions (on and off again) but it worked for me.
Solution 3:
There really isn't a solution with a speed of Remote Desktop on Windows, but the following article describes how to get the best experience possible.