They work well, but usually you will need to mount it so that the shaft is supported during the cut. You should also get an Arrow Squaring Device made by G5.
I used one for a couple of years with success, but my wife & kids gave me a Cabela's arrow saw for Fathers day last year. I wish that I had started with a real full size saw rather than the HF saw. You can do the job with the little saw, but you can get the job done faster and quieter with a full size saw. The Cabela's saws seem to be the best deal available on saws right now.
One thing that I just descovered that you can do with the Cabela's saw is that for about $30 you can jury rig a pretty good spine tester on it. That beats $250 or more for a Ram Tester.