I agree with the op that the success in MP is mostly about SA. As it was in real life. But there the comparison to the real life ends, this is the one topic where the 100% realism can`t be expected or achieved.
Because of the huge variety of the peoples hardware, it`s impossible to make absolutely realistic spotting in any game. I think the main goal should be to get it more or less even for everybody regardless of their display and settings. It means that it can`t be too `realistic`, because in that case people who happens to have hardware that is well suited (for some reason) for it, gets the advantage. Rest just can`t adjust their settings in any reasonable way to achieve same level of spotting and are in disadvantage.
It sure is not easy to find the right balance to the spotting regardless of players hardware and settings. But in this case the even playground is much better than the ultimate realism. That`s why I liked the alternative spotting more even with it`s flaws.