Special armors' largest issue is, IMO, their considerable BV cost. Think i was trying some idea out, swapping standard plate to reflective boosted BV nearly 20% (though SSW's BV calcs may be somewhat outdated). Considering that the armor types have their weaknesses, the BV costs feel too high.
This assuming they're used properly. Designs that mount special armors but don't really benefit from them are more questionable before BV is considered.