I don't trust microwaves, but I've never heard a convincing scientific explanation of what's wrong with them. The clearest warning I've heard is that they heat a few molecules to extremely high temperature instead of heating all the food evenly. Sous Vide is the opposite of that!

I think it's easy to trust something that's familiar in the home, like a microwave, but sous vide sounds a million times safer to me. I do have some concerns about the plastic (and who doesn't use THAT in a microwave?), but really, putting food under a mild vacuum is such a minor physical effect compared to bombarding it with radio-frequency energy. In my mind, the most significant "modern" aspect of sous vide cooking is precise temperature control. If anyone has a problem with that, I'd be very curious to hear about it.