When adding items that affect how the programme functions from a user standpoint, "Improvements" like Dynamic preview, Highlighting objects and undo (and similar type of items), there should always be an option to Toggle them on or off.
I must admit, a lot may be great idea's, but nearly every one affects the end users workflow, even if only that moving a highlighted item slows his computer down even a little bit. Not every user is running state of the art hardware, and slowing down the end product is never good.
CAD is supposed to make our jobs easier and faster. It seems that we're making it faster with one hand, and slowing it down again with the other!