I've been lurking a good while, waiting until I could contribute enough to this community with my leatherwork to come out of the shadows. But with all due respect, as an amateur black-/bladesmith I cannot get past this load of misinformation.
1 Modern anvils from reputable brands are still cast steel (either with or without a welded-on tool steel face) or forged steel in case of Peddinghaus. The stuff you buy at Harbour Freight and the like are indeed ASOs, but this by no means holds for all modern anvils. Vintage anvils can be junk too, so like with everything, buyer beware. If you're really interested in reading up on anvils, "Anvils in America" will tell you all you need to know.
2 A good anvil does not have to ring. My 275 lbs PFP (Peddinghaus) anvil does not ring AT ALL but it does have a ~95% rebound which is about as good as it gets. Forges like a dream.
3 NEVER whack an anvil with a hammer. First of all you can damage the face of the anvil, depending on the temper, even with very good anvils (you can also damage the hammer, but that's way easier to fix, although still undesirable). Second, depending on the rebound of said anvil, it is a perfect recipe for a hammer to the face (your face, not the anvil's). Any smith who ever missed his workpiece can attest to this. Third, if you want to piss off the smith you're visiting, this would be a good way to go about it, for reasons mentioned before. Never mess with a (wo-)man's tools.
Sorry to come on this strongly, especially as it's my first post.