I tested a 45Mb SWX assembly, which includes a CAD file imported from our customer. It took 21 min, 40 sec to import into Rhino, and the results were unusable:
I had one of our SWX guys remove the part, and the file imported into Rhino in 2 min, 4 sec. It was better, but there are still objects out of place (and not even supposed to be there):
When I imported the STEP file (that doesn’t have the customer part), it took 37 seconds, and imports perfectly:
All we do is import the customer file (which is always saved in Rhino format anyway) and we are good to go. Total time less than 1 minute.