I found Flash isn't too useful when the thing you want to trace has a lot of sharp corners (like a technical illustration) and a bit wooly. But it depends on the drawing. I don't like the results from Flash, so it's a taste question as well (so I import Streamlined art into Flash instead of tracing it inside) I use Streamline for print preparation and the handling of custom colors is very nice to speed things up (by changing them in Illustrator), while Flash handles anti-aliasing in a way that is very time-consuming.

So it also depends on what you want to do with the tracings. I just realized I streamlined a photo with extreme contrast . But couldn't use it in my design after all. This is an example of a vector tracing I myself couldn't get out of Flash when I tried.

Oh, I forgot, the issue was about not having Streamline. Then Flash is a nice alternative, yes.