on that note I agree with you, though adjusting FIX solutions to target different brokers in a "heartbeat" is quite a stretch. There is a reason most brokers require a "qualification procedure" before they let you off the leash....
On the execution side of the business, FIX is the standard. If your system works through FIX it can work through most big brokers, regardless of your choice of OS. When it comes to institutional order flow, almost 100% goes through fix.
Im not promoting to chose the broker based on a technical setup, Im promoting to select the technical setup where you are flexible to change to almost any broker in a heartbeat.
