I'm partial to the P209 for field notes. Big lines are handy and the thick lead won't break while I'm taking notes and being yelled at by the client. P205 is great for colored pencil lead for redlines and markups. You can find colored mechanical pencil lead at art stores. My field markups are the best.
Nothing's worse than trying to cook up As-Founds, As-Builts, or As-Installed with undecipherable markups. Is that a pipe tap? Or were you just testing the pen? Why did you scan in B/W? Why did the handwriting mysteriously change? Why put comments about a different project on these drawings?