There’s a useful post on Percy Balemans’ blog, Translation is an Art, about using CAT tools for non-repetitive texts: The Usefulness of CAT Tools.

She gives seven reasons why CAT tools can be useful even if your text is not repetitive.

Consistency
Even if texts are not repetitive, consistency is still important. The concordance feature in your CAT tool allows you to search for words or phrases so you can check how they were translated before. This is also very useful in case you haven’t got a terminology list (yet).
Quality control
These days, CAT tools offer more and more quality control options. You can have your translation checked for, among other things, correct punctuation, conversion of numbers, tags and consistent terminology. If, like me, you tend to mix up numbers (typing 1956 instead of 1965 for example), it’s good to know you no longer have to worry about this, because your CAT tool will warn you when you’ve made a mistake.

I’m really pleased to read this summary because when I started using a translation memory program – STAR Transit – in 1998, and much later, I would hear colleagues saying ‘You can’t use it for legal translation’. It really annoyed me when people who knew nothing about what the programs can do simply said to younger colleagues: Forget about CAT in your field.

Sure, the original idea of such software was that if you were translating a computer manual, for instance, and the same sentence came up frequently, you could automatically ensure that your approach remained the same. Your speed of translating would increase by many times (and you would fall into the grasp of those translation agencies who pay less if their source text is repetitive).

But those programs did more than just show you repetitions. My program links up to one or more terminology databases I’ve created over the years containing solutions to problems I’ve handled. It highlights in the German text the words I have recorded in my dictionaries. Nowadays, it even links to past translations and suggests phrases (I find this less useful for contract translations than I thought I would). It would allow me to check a translation against a glossary to see if I’ve been consistent. It will check all the numbers in a document to see if I’ve made a typo. It will also check a number of other routine things (see the quote above).

This quality control does not usually save me time. There are some cases where it speeds up working on a repetitive text – for instance, a client sends two almost-identical contracts, or an update of an earlier one. There I could use the function in Word to compare documents, but the CAT tool makes it much easier.

LATER NOTE: See also Jayne Fox on the same topic.