Quality brushes are important if you take care of them. The point, even on size 3, are sharper than cheap brushes, they hold paint better, and lay down paint smoother.
Their are at least two companies that people swear by..and more I'm sure:
Rapheal
Windsor and Newton S7
I use a W&NS7 size 2 almost predominantly, go to a 1 or 0 on fewer occasions as the points are just amazing.