Dimensions properties (arrow size, text height, etc, which may be set via menu Edit -> Current Drawing Preferences -> Dimensions) are measured in the same unit as all other objects in the draft.
This seems to be very inconvenient. For instance, having a huge object (here "huge" means a large number of draft units (100 or more)) and applying a dimension to it leads to tiny unreadable arrows and text on the dimesion line. So looks both on plot and print preview. Yes, I know I can change dimensions properties but this is just a workaround of the problem.
I suggest dimensions properties are to be measured in the same units as lines width (in millimeters in a case of metric system) and so we would have sane values relatively to paper size, not to model size.
The same suggession is for text inserting. However, it makes sense to have two kind of text sizes: relatively to the model (in draft units) and relatively to the paper.
Re - Dimensions, you can set up a layer with defined attributes such as Colour, Line weight and line type and use this layer to insert all your dimensions. If all dimensions are all on the same layer you can turn on and off the dimensions when you like and modify all (or single) to suit!
Hope this helps
Ok, I'll submit this to the Source Forge bug tracker on your advise.
Yes, I really kept all dimensions at a separate layer and I could modify their properties easily. But the problem is that desired "optimal" presets depend on such subtle things as model size. So it's quite difficult to prepare two different drafts with equally looking dimensions in PDF.