The Henson AL13+++ Aggressive is only slightly more aggressive than the Medium (++). In terms of effeciency, it achieves the same results in two passes—without irritation—that the Medium requires three passes to accomplish.
If you're torn between the Medium (++) and the Aggressive (+++), your choice should depend on your skin type. For sensitive skin, the Medium is the better option; three light passes will minimize irritation. For those with normal skin, the Aggressive is ideal, allowing you to achieve a close shave with just two passes.