nimh charge amps

Hi,
I have a bunch of 4200mah nimh packs, and my nimh charger (an Onyx 210) can do 3A or 5A. Is it ok to charge these packs at 5A (slightly above 1C), or should I stick with 3A?

(I also have a hyperion charger, but it is busy charging my lipos...)

Thanks
-Chief

Chief,
My Triton charge / discharge chart shows 2 hr charge current @ 2.1A, 1 hr @ 4.2A, and "quick charge" @ 7A for a 4200 mAh cell. At 3 amps, might take a while to charge, go with the 5A.
George