Let me say why I like industrial blocks so much..First off we do an insane ammount of slitting and drfiting..The different size holes are great for that..Accurately bending many sizes of stock in those holes is handy too..
One thing that I really like is you can use many sizes of hardys in the same block..I like to buy hardys when I can, saves us time from making them..If you have one size hardy hole either you need that size shank or you have to resize somehow..Or use a sleeve..
Now someone is going to say "but this way is cheaper or you can do it this way"..Thats all true but I like handy and I like multi-tools and i just flat like industrial swage blocks :D
As far as upsetting hardys in the anvil I dont personally like to do it..I dont doubt my big fisher can take it but on the other hand I personally have a hay-budden setting in my shop that I rebuilt after the previous owner broke off the heel right across the hardy hole..
*When you staring at your anvil, a 15# hammer in your hand looking at a anvil that was broken doing the same thing your getting ready to do it makes you pause :unsure: probably one in a hundred thing, may not ever happen again but i cant help but to think about it..