This is 100% better both in term of aesthetic and readability.
I'd say stick to hard brush even for super quick ones, especially if you wanna share them eventually.
Your sketch are very good it's a shame to ruin them with blurry lines.
When I want to keep it super loose but still retain sharpness I like to thumbnail instead of sketch. Picrel.
It's a good compromise, if you wanna be quick and sloppy to get ideas going.