As a matter of course, not all DryVit installations produced bad results or damaged homes.
Much of what occured in the DryVit fiasco was directly related to improper installation by contractors and not a result of the product itself.
But by time the real estate, insurance, and legal industries got involved, the product is now so stigmatized in the public's mind, that few venture to seriously consider a DryVit home.
Be that as it may, even if it costs you $100,000 to replace the entire outside of your home with brick, stucco, or some other finish system, you already KNOW you will have created at least $400,000 in equity if the original appraisal of $800,000 holds true.
That said, and if it were me, I would CERTAINLY buy this house and do exactly what you plan:
Remove the DryVit and replace it with a different siding.