Has anyone seen any improvements (better turbo response) come about from wrapping their stock exhaust manifold with header insulation?

Read about a guy that did this on an older 12 valve and he claimed to be able to tell a difference in the turbo response. Some of it seems a bit logical...if we can keep the EGT high before it hits the turbine, it will expand more and (in theory), provide more power to the compressor side.

Unfortunately, I assume there would be a noticeable increase in EGT's as well....which worries me since the stock manifold is prone to cracking.

Any input is always welcome! Thanks!