Are you having a problem with your current batteries? If not then there's no real need to switch.

The guy saying he can fly for a month without recharging would be foolish to not fully charge his batteries before a day of flying no matter what battery chemistry he is using.

Each battery type does bring some sort of advantage to the table as well as some sort of disadvantage. For the typical sport type planes that the vast majority of us fly NiCads and NimH are low cost, easy to work with and provide great reliability.

The only other batteries out there that really interest me are A-123's. I may give them a shot on the next larger plane I put together.