scale/grid sizes

Is there any advantage or disadvantage in creating objects in a certain scale?
I installed Blender and just used it for my first experiments like it was setup. As I was trying to create something that I would imagine would be in real live about 50 inches tall, I created it in Blender as 5 units high. Now I am using this model in a little 3D program and scale it. I did not try to change the settings in Blender yet to increase the grid size and so on, but are there any advantages or disadvantages if I make it factor 10 bigger? Like problems in navigating through the scene and so forth?

No, there aren’t any disadvantages. The Blender units are there for your convience and can be used in any way you like. One thing, though: Blender isn’t accurate enough for milimeter-precise architecture.
However, at enormous sizes (relative to the flat grid you see in the user view) you’ll see some strange things happening to your objects, like faces becoming transparant. There actually IS a limit to how far you can zoom out, so keep that in mind when scaling.

Cheers.

As said, there is an absolute limit to the clipping distances of both cameras; the one you view the 3D Viewport thru in OpenGL which can be accessed via View >> View Properties >> Clip Start and End, and the Camera Object (used for rendering) which you can look thru by hitting Numpad-Zero and adjust in F9 buttons, Camera tab with the Camera selected and active.

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