Tactical initiative is basically a useless skill on most escorts since they mostly have a Commander and Lt. Comm/Lt. tac boff slots. But on a science ship or cruiser that skill becomes very powerful. Also with some of the DOFFs (like the tac team conn officer) having a Tactically focused sci ship is very possible.
My Romulan Liberated Borg character made it to Level 30 and beat the (old) Defense of New Romulus with the skill point bug.
unless he uses the vesta , with its AUX cannons :p in which case having a high aux would be more beneficial
You can only mount 1 single Aux cannon per ship, which makes it a somewhat useless gimmick IMHO, as you are building a ship around 1 slot of 6, rather than building around the Tac captains inherent strengths, the advantages of sensor analysis, subsytems targetting and the ability to mount DHC + use of sci boff powers that are extemely destructive with low or no-aux.