I guess it is a simple tool. and no need much Calculation?
it looks like just 5 frames per second.
You’re wrong there: the move tool is more precise than the transform tool so it recalculates the entire changed area in the layer stack, and that’s very expensive. The transform tool uses a preview on top of the canvas, so that is faster.
ok~ but it is really slow than Photoshop… 
I never knew the details of it. When i find it hard to use i just transform. I thought i was such a smart ass when i realized that.
Are there any plans to improve this? I am not sure how Photoshop is able to do this much quicker. It would be a big time saver when just moving a layer without going into transform mode and still waiting for it to update.