My inclination would be towards the fewest conversions or reinterpretations, so the PDF straight from AutoCAD.
Unfortunately, there is no simple single answer to your question.
In general, Danny Whitehead's response represents best workflow practice.
But there are other considerations here.
There are at least three ways of producing PDF from AutoCAD other than trying to import the AutoCAD file into Adobe Illustrator.
(1) I believe that AutoCAD has its own native PDF export.
(2) Adobe provides a PDFMaker plug-in to AutoCAD as part of Adobe Acrobat Pro that also provides what is reported to be a higher quality PDF from AutoCAD.
(3) Brute force distillation of PostScript output from AutoCAD by printing to the AdobePDF PostScript printer driver instance installed by Acrobat.
Furthermore, much depends on the type of models you are exporting from AutoCAD. These could simply be wireframes or schematics or they could be full architectural renderings.
My advise is to experiment and see what actually works for your given AutoCAD projects and how each particular method either enhances, preserves, or even maybe degrades your original content. Choose what works best.
We'd be interested in knowing what you find and what you choose!
Oh,, and by the way, you certainly don't want to use EPS for anything in any modern workflow unless it's the last option available and nothing else works. EPS is so 20th century!
There are so many variables that no amount of expertise can tell you. You should construct your own text cases.