Tombow Dual Brush Markers

I recently bought the Tombow Dual Brush Marker in Grey Scale Palette.
I do Portraits in Black and White, so I wanted some markers that I can use for painting portraits, instead of graphite pencils. I want to use both techniques.
I decided for these markers. I like the fact that you can have dual brush, a fine tip for one side, and a soft brush for the other.

Pros:
-Dual Brush.
-Includes a Blender.
-Good Price.
-Good size, it's a long pencil.
-Feels comfortable.

Cons:
-If you have two layers, the second one will bleed.
-There are some colors that are pretty much alike.
-Instead of numbers, they should bring the percentage of Grey.

OVERALL: I think these are great markers, they're not expensive, it brings 10 for $14. The Copics, Prismacolor, or Faber Castell might be a better choice, but for this price, you would only get 8 or less. I think this is a good alternative for someone with small budget and who's starting painting with markers.