Originally Posted by Volucris
Solid capacitors have a much higher life expectancy in an even more demanding situation than do normal electrolytic capacitors. The former being of solid materials and the latter using a liquid.
The polymer caps seem most common in computer parts, motherboards mainly. They can't be that much more expensive if this cheap ECS board I got has them.
There must be some limitations to them then, otherwise I would imagine they'd be in everything, like this crappy TV I fixed.
Electrolytic capacitors are extremely simple, the quality ones probably are just as good to use.