The haircut does give a severe look to his face but I don't know if I'd qualify it as him looking more like a man...to me he looks like an chhila hua aloo in that haircut.
The mussed up hair suits him far better.
I have no idea what chhila hua means but I ended up laughing on reading the word. I don't understand why all the male actors feel the need to experiment with their looks so much on a single show. It tends to detract from the authenticity of the character unless the script demands for a change.
I liked Manik's initial look. We should also not forget how young Niti looks.