'Optifying' is not something users do. It's something done to apps during the development process. If apps have not been through this, they will eat up your rootfs when you install them, and by then the only thing the user can do is uninstall.

The problem is that some of the basic libraries (including the ones even the ovi apps rely on) are not yet fully optified. so you [b[will[/b] use a fair bit of the space however careful you are.

But in terms of the apps themselves, all the ones in Ovi, and in maemo-extras are optified. They have to have been optified to get that far. Apps still in testing (less so) and devel are (highly) likely not to have been optified. No point in doing that for every build of something that's still in very early experimentation. It's a sort of 'tidying up before public release' process.

Which gives you a fair idea of what you might want to uninstall.

If you still have 20% available (45mb) you should be ok for the Next big Thing.