I have one and I like it. My only complaints are that it seems every time I move it I have to readjust the feet, but that isn't hard to do... just a little annoying since I have to move it every time I replace the bobbin with my machine. It is also pretty static-y, but again that isn't a big deal, it just sucks up bits of thread underneath it and I have to clean the bottom off.
It is a much cheaper option than buying a special table though, I definitely think it is worth getting. I would go with the larger one though, the smaller one doesn't seem good for quilting.