For coil-spring spacer front-end lift kits, which is better?

Spacers that go inside the spring-strut assembly? or spacers that go
on top of the spring-strut assembly?

It would seem to me that spacers that go on top of the spring-strut
assembly would be better because they don't require a spring
compressor to disassemble the strut and because you can use the
original shocks. But I'm told, for reasons I'm not clear on, that
inside the strut spacers are better.

Any thoughts?

-Cyberbilly