Oh, thank you Orophin. I didn't think to ask about Legacy.

Malboro is a non-legacy world and seems to be mostly EST. I'm on the Pacific and I notice everything is crowded when I log on around 20:00 and mostly empty by 23:00 (weeknights).
Our free company is still somewhat small (we're up to 30!) but most of the people are on EST. We're friendly too! We have some people working through the main story (like me) and a regular group doing CT/coil runs on T/Th.

I can't speak to the other servers. You might try searching the Worlds/Companies section to see if people have posted their raid times to get an idea of when they are on?