"But will I be at a HUGE disadvantage playing MP with Lock On players who are not exposed to the same amount of realism?"
Just my take on the original question....Yes if the mission designer pits you in a KA-50 against fast movers, you would be at a disadvantage. This is due to DCS BS's realism, not LOMAC's level of realism. A good example of this is in ARMAII. KA-50 pwns fast movers left and right due to the lower realism settings for vikhrs. Fast , beyond line of site lock on via tab key = dead flyboys. In DCS BS you cannot simply "lock" a target via tab key so your job is much much harder.
On the mission design side, someone mentioned the BS being on the lower end of the food chain. This is a good point but I like to design missions with the chain being more a circle of life. Jets eat sharks, sams eat jets, sharks eat sams (if done right). By forcing the players to rely on each other for mutual survival on the battlefield makes for a more enjoyable experience in my opinion.