If you tend to like the sharpest blades and more aggressive razors, you probably have a tough, coarse beard. Also, for a lot of people, beards get coarser as you age. Since you indicated your beard is not so blonde anymore, I presume that means you have a few years behind you. If you can use a single DE blade for a week or more, you probably do not have a coarse beard.

Sensitive skin can mean a lot of things. Some folks are sensitive to specific soap ingredients and scents. Lanolin is one such ingredient. For me, triggers are lime, lemon, grapefruit, cinnamon, clove, peppermint and menthol scents. I can tolerate them in low concentrations only, thus, I prefer well-blended cologne type scents.

Sensitivity can also mean sensitivity various environmental issues. My face is easily burned by sun, heat, cold, wind and shaving. Many times people see me on a windy day and assume I have been on vacation in Florida. I bowl lather because face lathering causes brush irritation. I try to use brushes that have minimal scritch and scrub.

If I use an aggressive razor and a very sharp blade to tackle my coarse beard, the shave can be too harsh for my sensitive skin. Thus, when using DE razors, I have to pair my blades and razors carefully to be sharp enough, but not too harsh. I have a similar issue when honing straight razors. Getting the right balance between keen and smooth is always a challenge. It means that I rarely get more than three shaves from a DE blade and rarely more than 5-6 shaves from a straight razor before it needs to be refreshed.