Face AngleP21 has a slightly open face angle, P28 / Eichel / P28 / McDavid has a open face angle. A more open face lifts shots more easily; a more closed face keeps the puck lower.
Curve DepthP28 / Eichel / P28 / McDavid has a deeper curve (Deep) versus the slight P21. Deeper curves add puck control and shooting power but reduce backhand feel.
LieP21 has a lie of null, P28 / Eichel / P28 / McDavid has a lie of 5. P21 has a higher lie, which suits players who carry the puck close to their body.
Curve TypeP21 is a Mid curve (balanced and all-purpose). P28 / Eichel / P28 / McDavid is a Toe curve (toe-focused, better for wrist shots and toe drags).
Curve names don't match across brands, and the wrong one changes how the puck feels on your blade. Translate your curve to its exact equivalent on every brand in seconds.