Froyo apps2sd requires the App Developer to code the app to let it install on the sd card,some devs haven't bothered to do that yet.
The "pmsetinstalllocation2" sets the default location to store apps as the sd card,so even the apps where the dev hasn't bothered to code the apps2sd part can be stored on the sd,it doesn't work for all apps but most I found.
It still leaves part of the app on the internal memory though,and your widgets won't work if they're on the sd.
If your worried about space the rooted aps2sd+ method will gain you the most space.