Looking sweet, and well on your way to some decent sized colas. The 4 week mark IMO is a good indicator as to final yield. At this stage i like to see the pistils meeting each other up the stem, with a decent sized cola and the rest at the lower end of the branch almost meeting.
If it's like this, with the best weeks of budding still to come you are in for a good yield.
Your plants have something approaching this level.