Due to an issue with the Zen-Fire data provider I formerly used I am unable to trade and my broker has no ETA for when the issues will be resolved therefore I'm considering changing broker.
I'm looking at different factors, I found that the CFTC publish financial data on FCMs, so you can consider factors such as adjusted net capital, customer segregated funds etc for each FCM relative to each other.

See link below to PDF from the CFTC website with the latest data published;

http://www.cftc.gov/ucm/groups/public/@financialdataforfcms/documents/file/fcmdata1013.pdf


Another worthwhile link is the NFA where you can search for regulatory actions taken against any futures broker https://www.nfa.futures.org/basicnet


There's an article on Bloomberg from January last year looking at the ratio of excess capital relative to net adjusted capital for FCMs. May also be of interest.

"Adjusted net capital is the amount of regulatory capital available to meet the minimum net capital requirement as set by the CFTC. Excess net capital is the amount by which adjusted net capital exceeds the net capital requirement. The higher the ratio, the more capital the firm has available beyond what is required."

http://www.bloomberg.com/news/2013-01-15/cftc-registered-firms-excess-to-net-capital-ratios-table-.html