I look at it this way:
Every time the mob hits me, the RNG rolls against my Dodge skill (with whatever formula they use). If I succeed that dice roll, I Dodge, which just saved me anywhere from 1-900hp (talking exp mobs). So while a +8% to Dodge in and of itself may not be very spectacular... It still narrows the "failure" range in that RNG roll. And so I know I'll succeed more Dodge rolls with the augment.
I plan to stick the +8% on my Mir legs, soon as I can get enough wins there to buy 'em! (Nobody I group with frequently likes that camp, LOL).