Blender 2.8 sometimes freezes with imported file i work as an 3d artist with 3DS Max; and i thought to give Blender a try.

My problem started that Blender doesn't seem to have native import for IGS/IGES or other CAD files. I solved that by importing the object into 3DS Max and converting it into a OBJ file. (No big deal)

Trying to open the obj file is very slow and sometimes it seems Blender just gave up; but in the end it opens.
File size is 1.53Gb and the model has around 15.858.388 triangles.
As you can see the models i work with are quiet heavy.

But know i got my main problem; that's where my question is...
When i try to work with the model; even isolating an object; Blender sometimes freezes for a few seconds.

Am i doing something wrong?
Do i need to enable or disable some settings?
Can it be the obj file i exported?

Because everything works fine with 3DS Max; and i want to have the same experience with Blender.

I use the same PC for both programms, so i don't think it's the problem.
Intel Xeon v4 @ 2.20GHz
NVIDIA GeForce GTX 1070 Ti (MSI)
32GB RAM
I've just noticed that 3DS Max has an option to export OBJ file optimized for Blender.
That seems to be the solution apart from lowering the polycount on import from IGS file.

EDIT
After some tests i’ve got the following results:
Default import option: 15.858.388 triangles
Optimized import option: 557.088 triangles

Export to OBJ for Blender:
Default import + default export: 1.53Gb file (that’s a killer for Blender)
Optimized import + optimized export: 58.9 Mb