Don’t expect to see CMU piers…and that’s not a defect unless the pier/foundation is crumbling.
Floor joists often are not supported by ledgers (or hangers). That is a defect.
You’ll probably see galvanized piping (which I call out), cast iron drains, and may see knob and tube. Don’t assume that all K&T has been d-energized (I warn them about the possibility of the original wiring being in concealed spaces (walls, etc.).
I let them know the likelihood of poor or missing wall insulation. Missing sub-floor insulation is not a defect to me, but I certainly let them know it. Sub-standard ceiling insulation I do call out, recommending an upgrade.
Expect to see electrical and plumbing horror stories.