My experience is similar to Blue's. Work OK at low loads, but seems many can't realistically handle anywhere near the ratings as we use them. Also many PC supplies don't like the surges associated with charger starts and stops.

There is a possible solution though, server supplies are much more robust, are made to handle surges for hot swapping, and generally focus on just the 12V that we typically need. Widely available used, as servers tend to get updated a lot.