Thanks for replying back to me. The slowdown occurs regardless of whether editing is turned on or off. I am not sure what you mean by the "move to" drop list. Does it have anything to do with the screenshot below which is a sample output of what our categories page looks like?
Thanks for pointing out MDL-35179 for me. If that is the issue I am running into it is unfortunate that it may not be resolved soon but it is nice to know that it is being looked into.
Thanks for all the help!