How good, really, is Microsoft support?
When Munich talked about not supporting products alternative to available off the shelf commercial software--- I have trouble seeing the difference. Microsoft products have a big support requirement in a corporate environment, as do FOSS products. Is there much difference? It's not like you call Microsoft and they send you a fix for xxx problem. Most support is found online, and there is plenty of it, for both commercial and open source products ... with the big difference that if you have something really critical, you can patch your FOSS product. Try that with Microsoft products.
Munich suits got bought out by Microsoft suits. The arguments over support are bogus.
Now, to address specific software items you mentioned. GnuCash is certainly good, but Ledger, if you can stand working with text files and the command line, really does the job. Neither of them is especially suited to a multiuser environment, though, but there are some FOSS ERP projects out there. AutoCAD ---- not so much available at a pro level, unfortunately.