It could just be placebo, but like sullie said, I also feel port ack is a lot more stronger and efficient than those at the field. Perhaps its only because there's so much of them.. but whenever my squad attacks a port I give out warnings to the pilots, "becareful - port ack is murder".
I'm not sure if I want it changed though. The tension when jumping into a port to attack, is a lot higher than when going into a field to deack it.. and it's kinda fun.