Thanks Michael, I'm glad to hear that it is performing well for that!

In v4 in addition to the 64-bit-ness, there has also been performance work on CAD file imports to use multiple CPU cores when loading 3DM/STEP/IGES/SAT files and also improvements in the display engine to make use of larger amounts of VRAM on modern video cards. So those all go together pretty well for being able to handle heavy models that would have choked v3.

- Michael