I haven't found that the screens hang, but they can be rather sluggish. However, the flow of Panama keeps you hanging around longer than AdWords, so the sluggishness may be amplified in comparison. What I can accomplish with just a few clicks in AW takes 10 minutes of intense repetitive clicking in Panama. For example, take negative keywords. In AW I can set them at the campaign level. In Panama I have to set each AdGroup individually. What a pain. Same goes for ad optimization. Can't do it at the Campaign level, so you're forced into the repetitive mode again for each AdGroup. If you have a lot of AGs per campaign like I do, you spend a lot of time in their GUI, therefore waiting for pages to load, therefore thinking that they load slowly, etc. I hate to say it, but the Panama design team should have spent more time using the AW GUI instead of coming up with their own ideas. With AW as a model, perhaps they would have released an easier-to-use structure, and on time.