My questions are this- if you ever changed from being a regular employee to being a consultant (or a spouse/ SO did), what drove the change, and what factors would you consider for making the change?
I did that back in 1982. I had been planning to jump ship, but then my decision was forced by being laid off. I was then hired by the company for consulting work.
The biggest concern is the up and down nature of the income. If your spouse has a steady income, that helps enormously. Other benefits include the ability to save lots for retirement in a sheltered SEP-IRA account, and to have a health care plan that allows you to deduct medical expenses (may be different now). Another downside is extra worry.