Option 1...
It comes down to who you are playing with and against. If that's taken care of, then the emersion into the story can really develop. The greatest storyline will make little impact if the opposing force does not call thier hits, does not adhere to the game rules, does not immerse themselves into the story.
Sometimes a big shootem up is nice, but a detailed storyline with mission critical objectives layed out in a simple to follow plan is the best. Trigger time is crucial, but can be overcome with "superb" story and emmersion.
Reaching a "superb" emersion and game storyline becomes more problamatic when you are dealing with...
1. Greater numbers of players
2. Younger players
3. Inadequate location
I think an ideal game would be capped at an 8 on 8 squad player capacity, a well layed out and properly mapped location, limited use vehicles (with very strict story application), 2 long missions (am and pm), strict uniform requirements, 18 and over (maybe 21 and over), mag limits, and a very strong yet well hidden administration.
These are (to me) the core of a good OP. I may just impliment these in my next OP.