I can not remember seeing a B.E. product that was worth using and I have been playing for fifteen years!
Selling any markers in High Street stores is irresponsible, Its started in this country with shops like Argos.
Viewloader and JT were bought by B.E. with a quality product range in place. I believe that there was an agreement that they would not interfere for a certain length of time.
Black Revvy shells are fine, the clear and colours have always been brittle.
As for Eggs, my son bought an Egg 1 and the feed neck broke off second time he used it. One of our team has an Egg 2 and it feels no stronger.