I agree and there are a lot of settings that can help prevent this, The one thing I know that helps this along the most is if I open an app in portrait mode and and while in the app switch to landscape mode and then try to go home in landscape mode (and Vice Versa) Launcher Pro has to completely rethink itself. If I go back to portrait before closing out the app the "keep in memory" mode within the Launcher Pro settings will usually take care of the restwhen it reloads after using an app for a while it renders my phone completely useless for about 10 to 15 seconds. Thats a lot of waiting.
All in all, the best Launcher out there