Machine Translation is not the only activity where there is a trade-off between quality and speed. Metrics for measuring time are clear and universally accepted. This is not the case with metrics for quality. However it is possible to broadly rank qualities of translations done by people or machines.
Also I think that after a little reflection most people would agree that the relationship of this trade-off is not linear. With this I mean that it is, in general, not true that spending twice the time on a translation its quality will also double. Very quickly a law of diminishing returns sets in, and it gets harder and harder to make the translation better.
Exploring the issue from the other direction, it is not difficult to produce a translation almost instantaneously, but of appalling quality. The question is whether it is meaningful to talk about “striking the right balance” in this context. I think that it is meaningful, but the right balance will be different for different kinds of documents.
Among other things, computers have got a big advantage over humans in that they don’t get stressed, be it for deadlines or any other consideration. Tell the machine what you want from it, and it will go about the task as fast (or as slowly, it cuts both ways) as it can. Therefore, for projects that run against the clock they might be the best tool available for reaching the goal. Even though the rest of the agents in the chain can feel under pressure, at least the translation step will have a consistent cost in time and quality.
If you need to translate documents at short notice, you can contact us at Translation Services to explore the alternatives available.