>If you in the middle between introverted and extroverted, working alone may work if other parts of your life have personal interaction.

I think this is a good point, and for me one of the scarier aspects of this type of work. Working alone is fine until it isn't. I think your work quality / satisfaction are always going to be relient on your out of work happiness to a large extent, but when you're working alone there's that much less of a buffer. Work is such a large part of our lives, doing it alone is a pretty large commitment to aloneness.