I'm undecided,I'd have to see more evidence from other experienced keepers. I don't think they'd offer much more nutritionally would they? and I don't think the snakes give a toss about a diet variance. Ray said fish were good if you couldn't get Rats or Mice but I think I'd sooner let them miss a meal then chance giving them fish. He said they were a lot cheaper than Rats and Mice which is true but if there is a major concern about how expensive it is to feed snakes then I reckon he's got too many to feed.
Cheers, Greg.