"They do exactly what you would expect from them, not more and not less, they are very sharp. It's walways handy to have some spare blades with you in that lttle container they come in.
When they snap "3 or 4 a time" they are not being used as intended. The blades are not supposed to be used fully retracted from the knife handle. If you need to bend them always do with the grooves on the inside of the bend otherwise they will snap quickly (that's what they're designed for!), causing nasty injuries."
"...you are always forgetting to snap off the blades as these do it for you, usually 3 or 4 blades at a time - I was actually glad to finish the pack as it was really annoying, and it's not as if you can send them back!"