Not too far back, we did a lot of talking about nano regen clusters. We wooted a lot and told everybody they'd get +110 nano every 10 sec with QL200 implants in.
Turns out that's not 100% true. Got in trouble with an enf in my guild because he redid his implants, but was only getting nano about every 30 sec. It wasn't anywhere near as nice as I'd told him it would be.
At this point, it appears that the rate of nano regen is tied to Psychic. In the most straightforward test we could come up with, the enforcer raised his Psychic by 40 points and his nano regen rate improved by about 4 sec.
In asking other people what their Psychic was and how fast their nano ticked, we think Psychic may not be the only factor. But it clearly is at least one factor.
So, bottom line is that your mileage may vary with these implants and Atroxes get the short end of this particular stick because of their lower breed max.