This is how I use DVD-RAM:
Constantly saving all important programs and data files with a simple drag-and-drop (or cut/copy and paste) to the disc. As new versions of programs come out, I simply drag & drop to the disc. I also save my files to the disc directly in office-type applications and graphics applications. So it works similar to a hard drive, floppy drive or USB key. I download direct-to-disc and can also play some files and save/edit files on the disc in another program while that's happening. It's as flexible as you'd expect a hard-drive to be with saves and edits.
*Saving stuff to the hard drive. Very fast speed. But a hard drive can fail at any time and take your data with it. Want a safe back-up? You are still left with the hassle of backing up your stuff the old-fashioned way (ie. loading up Nero (or similar) and pre-mastering on DVD+R(W) or DVD-R(W). This is still extremely slow on 4x media (and still would be a pain with 8x, in my opinion), and you don't really have the quick flexibility of making quick changes to what you save to disc like DVD-RAM, which is the major drawback.
*Or you can save stuff to direct to regular DVD+R(W)/DVD-R(W) with packet-writing applications if you want the same drag-n-drop ease, at the expense of reliability and data integrity (the way the data is written, the drives and the media itself are far less reliable than DVD-RAM). Do you trust less stable DVD+RW and DVD-RW media and iffy packet-writing applications enough with your data? I don't.
In summary, DVD-RAM is a great format for daily saves and edits on the PC, without the risk of a hard drive crash taking your data. To me it beats the pants off pre-mastering in Nero, and I don't trust my data to packet-writing to get the same convenience (or reliability). Several DVD drives out there can read DVD-RAM like some Pioneer and Samsung models and others, but sure, DVD-RAM playback (and recording) support isn't as common as regular vanilla DVD-R(W) and DVD+R(W). How important is sharing your data with others? If it's important, burn off a quick DVD+R(W) or DVD-R(W).
It all comes down to what your priorities are. I think the format fits its niche quite well, and is unmatched in the areas it excels in.