Well, Major downside of WWE and especially WW is that opponent gets to play first after that. If even slightly prepared, he can easily take advantage of new positions. While WW/WWE player might in general be better prepared, losing one card and giving opponent option to react first is surprisingly big disadvantage. Sure it might sometimes be annoying, but it also can be fun. Like when your perma-encumbered warrior with Obliterating Bludgeon lands next to a wizard.