Here's what the default island looks like. It pretty much has an autogen object for every object on the texture, which is the way to do it. It beleive the default is at 1m but it might be higher. Certainly the airports have more detail in the add on but the default island is hard to beat.
Edit: oops this quote is by Sillyeagle
it seems your right. i flew around with the default settings and the only major changes are the airports and close surrounding areas a bit. and the other two islands other than st. maarten have also major airport changes and the immediate surroundings but the rest of the island look like the default mesh to me anyway.