How long do metal and carbon film resistors last?

[pseudoistor]

Hello,

I've read that metal film resistors are better than carbon film because they're resistance remains constant even when they heat up from being soldered. And I know they're suppose to be more precise with a 1% variance instead of 5% of the carbon films.

I know capacitors go bad - do resistors? What is the shelf life of the carbon films and the metal films?
In your opinion, is it worth paying more for the metal films for the advantages? Specifically, for longer-term storage and being used in applications that use a high frequency.

Thanks

 

[Elledan]

Seems like it's mostly a function of environmental factors: http://en.wikipedia.org/wiki/Resistor#Failure_modes

Like every part, resistors can fail in normal use. Thermal and mechanical stress, humidity, etc., can play a part. Carbon composition resistors and metal film resistors typically fail as open circuits. Carbon-film resistors may decrease or increase in resistance.[16] Carbon film and composition resistors can open if running close to their maximum dissipation. This is also possible but less likely with metal film and wirewound resistors. If not enclosed, wirewound resistors can corrode. The resistance of carbon composition resistors are prone to drift over time and are easily damaged by excessive heat in soldering (the binder evaporates). Variable resistors become electrically noisy as they wear.

All resistors can be destroyed, usually by going open-circuit, if subjected to excessive current due to failure of other components or accident.

I very much doubt that the average resistor won't make at least 15 years in the right conditions.