Hi Rojo,
I don't have a ball bearing so I haven't done that test, however it does rebound a hammer well when lightly tapped.
The positives at this point seem to be:
-Easy to tie down with the 4 bolt holes.
-Hardness appears correct when tested (with testing files).
-Lots of mass under the commonly used area.
-Easily cheaper than other options and still half the price of a near wrecked antique anvil here in Aus.
Negatives:
-The 'as cast' finish corrodes quickly. This is easily wire wheeled off but leaves discolouration.
-Maybe not as attractive as some.
-It took quite a while to flap disk the 'as cast' finish that was left on the horn.
-The horn it quite blunt, however I have heard that some deliberately do this to avoid injury.
-3/4" hardy hole. I could have waited for the new design with a 1", however I wanted it immediately.
I am still very happy with the purchase (especially for the price) and the weight of the combined package is still moveable whilst being solid and not wandering.
Nick.