Sorry, I only knew they used Redi because they clear GSEC. Why Redi? I used it for many years and was not impressed. Might be better now. I stopped using it in early 2010. My firm offers it but I'm not sure if anyone uses it.
On another note, if you expect "customer service" when you join a prop firm, you will be disappointed.
As we talked in private I´m looking for a vertical DOM to trade stocks and REDI has it. That´s why I´m looking for a prop with such tool (among other requests).
And I must admit that most of the props I´ve contacted have very bad customer service as most of them not even response to mails. But some of them seems to be serious.