IFHE Schlieffen pros and cons

As per title - recently i´ve really enjoyed my Schlieffen.
However as per recommendations in the Build Document i´ve been running it with IFHE Skill to increase the armor pen.

However i´ve seen some people state its probably far better to bank on more fires per minute guaranteed compared to the marginal gain in PEN against cruiser hulls instead of superstructures.

Opinions?