Jeff the issues with respect to tactical philosophy vary greatly between large unit operators and very small unit operators for all the obvious reasons. IR has a great advantage in that it retains the unit's tactical or clandestine advantage provided the other side is not equipped to pick up the IR illumination if active systems are used. A Ranger fire team, for example, will be much larger than a SEAL boat crew or squad. Workit espouses the use of IR for strong hold approach and is probably using Bravo 7 head gear. In an open field this gear works well but remember that there is a restricting visual cone of (20, or so degrees?) which means that close in objects are not visible unless the user sweeps his vision pattern up and down - back and forth this is not easy to do in close in situations that occur inside rooms where the field of view becomes more restricted as objects get closer. Outside in open areas it is not as problematic because we are normally looking out several yards away where the vision field gets broader with distance from viewed objects.
Some of the SEAL teams use bravo 7 gear as well but they also have gone to monocular gear which provides for ambient, complete peripheral vision with one eye ( preferably the dominant or shooting eye) in any case they will always opt for tactical profile before giving in to convenience as they do not normally have as much fire power to get out of trouble.