McDwiff connects to Autodesk's online DWF translator, so accuracy is always 100%. Of course this means your DWF is being uploaded to Autodesk servers, so don't use McDwiff unless you're OK with that. It's all private and stuff, but you never know.
Open any DWF (2D or 3D) on your Mac, just like any other file type. 3D files open, but 3D rotation is still "in the oven", so to speak.
Fast zooming and panning - McDwiff uses predictive image processing, supports multipage DWF files, lets you print DWFs, and can export DWF to TIF, GIF, JPG, PNG, BMP, or PDF.