A DMG file is, effectively, a Mountable ZIP file. The "typical" Mac Installation process is to open the DMG file, a window appears with the Application bundle and a link to the Applications directory, and a big arrow, essentially telling you to drag the App in to the Applications folder.
That's a "mac install". That's a "friendly" mac install. Digging stuff out of zip files is not as "mac friendly". Tim's point of moving to an Installer to essentially "force" folks to actually drag the app off of the DMG is interesting, and, honestly, not surprising. Because I know I've launched apps off of the DMG. Sometimes, I have just left them there. And I can certainly appreciate how it's a problem for something like NetBeans. NetBeans is almost 6000 files (!!), that's a lot of random seeking against a compressed stream in contrast to maybe a linked executable loading it a swarm of shared libraries from the OS. No wonder it's slow. The Installer never bothered me, I like the current installer. My only concern was that it needed admin rights. Not that I don't trust it, I just don't like apps that need admin rights - mostly because it acclimates users to just hit "OK" for every program install, which just leads to trouble.
