It is possible to make a transfer by just making a videotape of a projection. But framerates for projectors don't generally align with framerates for video, so some modification of the projector are usually required. The standard way to do this is to use a 5-blade shutter instead of the 3-blade, in conjunction with adjusting the speed of the projector. There is a nice virtualdub filter for reducing any residual flicker that might result from any remaining variation.
The advantage of using the workprinter, on the other hand, is that you get an exact frame-by-frame correspondance between the film and the video. Since most players are capable of then performing the pulldown from the film frame rate to video frame rate, it usually results in cleaner motion. They are also much easier to work with in post.
I sometimes use the method of filming off of a projection, when circumstances dictate. For example, on films that have shrunk so much that the workprinter won't play them properly.