I pay someone to create CAD Designs for me. Each time I upload a CAD Design the sizes are incorrect via "Obj", and the prices are out of this world for the size i'm looking to get. Which would you recommend I use for future purposes?
If the problem is model scale, the problem is probably assumed scale, not the file format. Making a guess, the model is in mm (which would be preferred for shapeways and most 3D printing software) but a scale "correction" is being applied as if the model you upload were in inches.