I was using a SelectField before the changes related to popovers (release 0.14.0-rc2). The menu has about 400 items to choose from. Before, expanding and collapsing the menu was very fast (almost instant) but with the popover change it is quite slow (.5-1 second). I have verified that this performance change happened in 0.14.0-rc2 by switching back and forth between that and 0.14.0-rc1, and observe fast expand/collapse in rc1 but slow expand/collapse in rc2. Has anyone else noticed a similar performance hit? Was there any testing done with large lists of menuItems?

It's a bummer because the popover is giving us lots of nice features (such as actually being able to scroll through the menu items :) ) we were looking for but as is, we cannot use it.