Here's a free service that updates each minute and shows quote frequency across all the US equities and options feeds.

http://marketdatapeaks.com/

I have not figured out a way to make it useful, though I have noticed that sometimes quote bursts occur very near the same time that liquidity is pulled in the ES though the proprietary method I've document here prior.

Ellis and I did substantial research on the history of the NYSE post-IPO, including the flash crash, and found some interesting things that I will put together and write about in the coming months. For now, what he posted is good background. And, indeed, high liquidity and decent operational control by the CME of its exchange is why I prefer to trade the ES.