Ok, I`ll give my opinion, not about your performance relative to the mono`s since i don`t know them, but on downwind angles etc.
Nick, It`s difficult to know what you`re doing relative to another Mozzie since you were the only one there. Have sailed H16, Mozzie, Dart18 and others - Dart18 is critical at which point in windstrength you swop from low`n-slow to high and fast, H16 a little less critical. Mozzie likes to reach fairly deep, the gain in speed going high is sometimes not worth the extra distance covered, mainly in light wind (less than 10knots). The tricky part is knowing(feeling) at which point it works for you to heat it up and building apparent wind. For me it is over 10-12knots, depends on crew weight, sail cut, boat weight etc. Obvious tricks are ease downhaul & outhaul to suit conditions. In some triangle-sausage-triangle races, we have actually sailed 3 triangles, gybing around B-mark on the sausage, as it gave the best VMG downwind.(mainly in strong wind).
In one race I was blanketed by about 6 boats going into B-mark, they all sailed over me and gybed at the mark, the next leg to C was very deep, so I sailed 200m or so past B-mark and then gybed, gaining back my six places at C-mark !
Best rule-of-thumb is to have streamers on your bridle wires, and try to keep them streaming at 90deg to the boat.
Forgive me if you know all this already, but there might be something useful.

Steve