The flash trigger saves both battery power and reduces recycle time of the on-camera flash (especially when shooting in TTL).
I do think it also recycles faster compared to internal flash at low manual power but I have not tested that.
Unfortunately I already bought the Nauticam trigger, the O-turtle looks promising. Does anyone know if this trigger reduces TTL accuracy?
The TTL question :
We set the TURTLE to the perfect TTL mode, and try to tried all possibilities in surface and underwater also. If we find a bug in the software we repair this.
We are in contact few professional photographer who test the products and we will make an article with testphotos for o-TURTLE and Olympus systems as soon as possible.
The recharging and overheating is a problem if somebody use the internal flashes. Usually use more the 75% power in the internal flash for the perfect wideangle pictures. I think the internal flash makes 5-10 pictures in a minute and will be owerheat. The LED triggers works continuosly . The limit is the underwater strobe capacity.
The second problem with the internal flashes is the flash tube characteristic. The internal flash and the underwater strobe characteristic not same. Just let's see the tube size!
I hope we can gives helpful answers.
Have a nice day