Is the fire pit built on a footing? Is there a drain system within the center? Are there weep holes for air to keep the fire from burning itself out? I agree larger stones for the cap would have looked better. What mortar did you use to keep it from cracking with the heat from the fire?
I am only asking to help you out, I have done dozens of these and there are a few simple extras that will make you stand out from the other "contractors".
When the fire gets hot I have noticed that the mortar joints will crack. Mix Type N with some fire clay and that seems to help that from happening.
You seem to take alot of pride in your work and in this industry that will set you apart. I am more of a lurker that a poster I will ahve to post some of our hardscape work soon.