No they are not. There is ONE exchange for Micros. CFDs... as many market makers for each broker as the stars.
As products, they are the same as I mentioned spread, margin, etc. Yes, the brokerages are different. Anyhow, the situation is the same as with online gambling. The US says: we don't want the citizenry to lose their money to Bahama based websites, when they can lose it to Vegas based websites.