At what point would you step up to ferrea hollow stem valves

I get it.....I guess what I should have said was, IMO it's splittin the HELL out of hairs to take a chance on using hollow valves. Valves crack and break sometimes as it is. Yall use that ****. I'm stickin with with solid ones.
I won't even use those small diameter solid valves.
Good old 3/8 mopar performance valves in my small block.