I did a postdoc at a top 5 institution and found it to be an ideal transition point into the startup world. I was pretty sure a few months into it that I would leave academia, and spent as much time as possible beefing up my coding skills and doing a startup on the side/finding a cofounder. I even hedged my bets and applied for tenure track jobs in the meantime. This may not work for everyone but it was definitely better than doing a full time industry job during those years which would have made any substantial entrepreneurial activities much harder to do on the side, and not nearly as good for networking.