When you buy pre built surface packs they show a reflection looking perfect in the model used to show the surfaces you've bought.
If you build a simple model and apply the new surface you often won't get as nice a reflection which is usually attributed to the scale of your model vs. the size the model the surface was applied to when it was created and sold.
I understand you can scale your model to get closer and there is no limit to ways you can tile the reflection map or environmental map to get a good approximation.
What I'm looking for is the following:
Is there a general rule of thumb as to the size models are built in to match what most professionals use when creating their surface libraries?
I try to build things as close to actual scale but this is often very different from pre built libraries.