The big difference between Aetna and Baymac is that Baymac is not a "supplemental" coverage, i.e. its not used to "top up" EK medical insurance.
Unfortunately not true anymore. All claims have to go through EK and only when over and above EK policy can be submitted to Baymac. Reconfirmed with the office and was told, this was always the case but will be reinforced from now on.
It can be used as stand alone if no other health insurance available but with some countries excluded!!