As someone who works for a company who pays profit sharing, trust me when I say that you're almost surely better off taking the $ as part of your regular salary. Profits come and go, vary in size, can be easily impacted by one-time charges, etc. and are not a reliable source of regular income. In addition, with the $ baked into salary, you get the compounding effect of future year increases, etc.
The company I work for made a nice profit this year as far as Wall St is concerned. However, we didn't meet our "internal" numbers. Therefore, no profit sharing. Everyone is very upset. I would much rather have had more baked into my salary to not have to deal with the ups and downs of profit sharing.