....thank you that is what I thought.
When it comes to the higher grades of Security, SWAT and Military Grade armours which have higher capacity -6 capacity is somewhat more manageable particularly since all helmets have their own capacity ratings for sensors, comm gear, tactical links & such.
The trade off between the two is either a better chance go to get it (and not pay a lot of markup because of the + 6 availability for the FBA version which for the heavier armours can get very expensive), or like you mention be able to mod out your armour more.
Not that I myself would have a character running around in SWAT, Security, or M.G. armour as they tend to draw a high degree of attention. Granted, the one advantage of SWAT armour is it is not restrictive like Security, Riot, and Military Grade armours are, though you still stand out in a crowd and when in the Barrens it's like wearing a "Shoot Here" sign (and someone there is bound to have a high powered S/A rifle or shotgun with AP rounds).