NiCad have their use, things like cordless drills where you can stall the motor and cause it to pull a lot of current. But for standard sizes like AA and AAA NiMH have at least twice the capacity in the low self discharge (Eneloop, Hybrid, nybrios, etc) up to alomst three times the capacity with some of the 2700-2800mAH batteries out there and with a quality charger can last a long time. I'm still using some 1650mAh NiMH from 1999 in our baby monitor and after switching to a decent charger they are running it for 2-3 weeks between charges.