OK, so I've checked the FAQ and the errata and found nothing about this.

For the adept power Improved Reflexes (pg 188, BBB), it says that "For each level, you receive +1 dice to Reaction (this also affects Initiative) and 1 extra Initiative Pass."

I interpret this as providing +1 IP and +1 Reaction, like Wired Reflexes does. However, one of my players (the one who has it) interprets it as providing +1 IP (here we agree) but +1 die to Reaction tests, as per Combat Sense or Reakt or whatever). Which of us has it right?

Thanks,
Joe

It improves the Reaction Attribute and gives one extra initiative pass per level.

So yes, they will have a faster reaction time to dodging, driving a car ets as the brain manages to interpret information faster.

Brilliant, thank you.

The catch here is to remember that it's an increase to the attribute, and not a dice pool modifier. So, it's affected by the augmented cap.