To strike or not to strike?

There is much talk at the moment about the possibility of industrial action against cuts to public sector pensions. Public sector trade unions are balloting their members over whether or not to take strike action.
I believe that all workers have the right to withdraw their labour at any time they choose, and I oppose the oppressive anti-union legislation currently in force in this country which places restrictions on this right. However, I believe that strike action is rarely in the best interests of workers. Whether in the private or the public sector, it is almost always the case that the employer is in a far stronger position than the workers when it comes to the war of attrition that a strike entails. In other words, the employer can usually survive for longer without new profit being generated than the workers can survive without pay. Even in the case of a general strike, in a sense the workers are cutting off their nose to spite their collective face. Why should workers allow themselves to be forced into a position where they cease to produce the very goods and services that they depend on for their own wellbeing, either directly or through their pay?
In my own area of employment, the NHS, the public sector workers' union, UNISON, is balloting its members over whether to take part in a one day strike next month. Unfortunately, being very familiar with the culture of the NHS, I am fairly sure that most of the strikers will, when they return to work the next day, work twice as hard as usual in order to catch up on the work they weren't able to do the previous day. In the end, productivity will not have suffered and the Department of Health will have saved itself a day's pay for several hundred thousand health workers.
If industrial action is to be taken then, before the drastic step of strike action, a work-to-rule or go-slow might prove effective in some cases; it would damage productivity while allowing workers to continue drawing pay, which would not only be less harmful to the workers but would also allow for a more protracted campaign.