I've got the nicad and used the lithium one a lot and I prefer the nicad, it just feels better. It's heavier and just feels better when you're trying to undo something stubborn a bit like the difference between trying to break a lobster claw with a hammer on an anvil or trying to do it on the kitchen sink. Feels more solid when it hammers with the extra counter weight of the battery

I work mobile and find the lithium batteries don't last as long in the cold weather.

I've had mine a long time and it gets used every day and it's still going strong.