Here are some comparison shots between the Focus R21 with the plastic insert and a similar Focus shavette with a steel insert. Apart from the inserts, the two razors are almost identical. But the stainless steel portion is angled more steeply where it meets with the blade in the steel insert.
Plastic and steel insert models with their inserts removed.
Plastic insert with half of the Lord Super Chrome blade loaded as compared to the metal insert with the other half of the blade loaded. Very difficult to achieve a proper alignment with the blade snapped in half, and there's no way that I wanted to shave with things as they stood there. Note that the plastic insert shrouds the blade corners whereas the steel insert does not.
Switched to a Lord "saloon-style" dedicated half blade for the metal insert. Line up went much easier, as shown with less blade exposure, yet the corners of the blade are still exposed. This was acceptable to me, so I shaved with it to see what the result would be.
Plastic and steel insert models with their inserts removed.
Plastic insert with half of the Lord Super Chrome blade loaded as compared to the metal insert with the other half of the blade loaded. Very difficult to achieve a proper alignment with the blade snapped in half, and there's no way that I wanted to shave with things as they stood there. Note that the plastic insert shrouds the blade corners whereas the steel insert does not.
Switched to a Lord "saloon-style" dedicated half blade for the metal insert. Line up went much easier, as shown with less blade exposure, yet the corners of the blade are still exposed. This was acceptable to me, so I shaved with it to see what the result would be.