i would agree with both of what was said above. there are a lot of people going towards the employee vs completely private because of the security. things to consider are your location, the payor mix, and the medical climate in that particular area.
location can be an issue if you are in a specialty that is very well represented in a location and/or you are not in with the major groups. as a new person, this will be tough going. if you are moving to a area that has a high medicaid population, employee or academic. let the hospital eat that cost burden. if an area has only 2 large medical insurers that drive care, be careful because if you do not par with them this can be trouble. high malpractice location in a high malpractice field, you may want someone who is self issued covering you (malpractice in some areas can be $50-200,000 per year for those high risk speicalties)
and for those going into a private practice model (single specialty or multispecialty) as pilot doc said, you are a small business. you really have to be business minded. "you eat what you kill." if you don't collect enough to cover you overhead, you don't get paid. take vacation or get sick, no bills go out, collections drop, no income. as a partner, there are some significant benefits, but most have a "buy in" to the partnership (a friend of my is buying in to his urology practice now, i think the buy in is $300,000)
so as stated previous, employ less risk, less gain; private more risk, more gain.