Cynical_ManI have both. The Sheepskins definitely add more to the low end (not a ton, but it is a welcome increase) and makes them a bit more V-shaped (just more so over their current FR). The hybrids add some more to the lows as well, but not as much as the sheepskin and more to the mids and highs as well - a more gentle V-shape.
I personally keep the sheepskin pads on them as they're closest to the Stellia pad and push the Elegia in that direction FR wise.