Quantrix is used a great deal in finance, and I have the impression that it is used more than Excel by people who need to have confidence that their financial models are correct.
I wasn't precise enough, I meant financial departments within companies of all areas. Finance as in banking of course has its special tools - but I would be surprised if Excel is not used for anything quick and dirty.
MS Excel is not precise enough in a lot of areas, you can't compare it to something like SPSS for statistics for example - but it's good enough.
