Here's something to try with a Rev... It seems quite hard for some people and easy for others but should help with control somehow.
Hold the kite in the centre of the window with the LE facing right and try and hold as still as possible. At this point your hands should be holding the handles in the vertical position but most people started doing this the first few times with the handles following the kite. So for this exercise hold the handles with the left above the right (or vice versa if the LE is facing left) in a horizontal plane. Then try and hold the kite as still as possible again.
Now the hard part. While keeping the same amount of brake on each line and the same distance between left and right (the upper wing will be nearer you to maintain the hover) rotate both arms 180 degrees anti clockwise and try and maintain the hover. Now the tops of the handles are pointing left towards the bottom of the kite, your brain will hurt and if you're still in control you're doing well.
Jason.