The Set Add. effect does not require the entire set to operate. For every piece after the first of this set that you acquire and equip, you are awarded 10 bonus HP. Even if the entire set may not meet your needs, you can still get some pretty sweet perks just using the armet and cuisses, which are better than the non-AF options at this level or higher.
I used this set ad PLD (minus the hands) until i got all my AF. as a taru the HP bonus was well worth the armors. DEFINITELY recommended for any paladin
No reason to ever use these over R.K. Breeches, even for PLD. The offensive benefits on the breeches vastly surpass the AGI and set bonus on these, especially at 55+ going into Lesser Colibri where more damage = more hate and killing faster.