Advantages of NIMH over NICAD
1. Same weight NiMH will have 1.5 to 3 times the capacity of a Nicad.
2. Same capacity NIMH will come in a much smaller lighter package.
3. No memory worries.
Advantages of NICAD over NIMH
1. Nicads can "dump" their power quicker. Thus, they "can be" better ultra high drain applications like electric motor power packs. Note, were talking about dumping a pack in 20 minutes or less here, not RX and servo loads.
2. More tolerant of abusive overcharge.
3. Your current quick charger will charge it for sure.