I was a developer in the most recent auction and it was a great experience.
As a developer it appeared the only required field for employers was salary. Often equity, vacation days and perks were listed but sometimes they were listed as negotiable. All but one of the offers I received were for significant raises above my previous salary. And the offers included some from high profile companies.
Once you receive an offer you have the choice to either interview with the company or decline to interview. I actually chose to decline three of the six interview offers I received because one company looked like a horrible fit off the bat, one company offered a small raise but required moving to the bay area (which I was open to for the right circumstances but not that one) and one company offered me a salary below my current salary (Developer Auction allows you to set a minimum salary it would require for you to consider moving to another company, I actually listed my minimum as below my current salary to try to leave open the possibility of moving to an early stage company).
If you choose to interview with a company the process proceeds as it would normally and you may have still have to go through a rigorous hiring process. The purpose of the site is less to create an actual auction and more to shift the power in the hiring process toward the employee. It really helps you do a comprehensive job search with a lot of companies in a short amount of time. It solves the job search problem of accepting an offer and wondering if something else is out there that's a better fit. All in all it was a great way to look for new opportunities and I ended up accepting an offer from one of the companies I interviewed with.