It all depends on what he wants. There is nothing new under the sun.
If he wants the latest and that matters get the E521's. They are an iron wood club. The C521 is more of a comparison to the HL3. Personally, I could not play that set due to the looks.
If he wants a more traditional looking club go with the HL3. Save a few bucks too.
There is probably not much difference in actual playability.