There was some speculation a few years back that barbless hooks would actually penetrate better, but I don't think it was backed by any solid evidence. There are really too many variables when it comes to a real live fish on a real live hook. Most people don't fish with optimally sharp hooks, anyway -- very few people ever sharpen a hook.

What's certain is that barbless won't hold as well, except on very small hooks (i.e. #18 or smaller) where the barb is more or less irrelevant. Barbless hooks will hold a fish if you keep constant pressure, but not if you relax that pressure. That makes them unsuitable for any kind of set line, which in a survival situation is generally your best method of fishing.

I do use them for all my normal fishing, though, as they're easier to remove from my own anatomy....