cons: They go out faster than LED lights, they produce heat, they require converters to work (messy case / cable routing sometimes), they can go out (the inverter, at least)... They aren't quite the color you want (in my experience
) My red cathodes look orange, the blue ones are like.. baby blue
I've owned about... ten of the cathodes and have had only one go out on me in the last two years.
More Pros when in comparison to LED strips: They can be turned off and on with a switch, they're brighter.