They are 1.2Kg/2.6lbs so make stepping the mast a little more difficult on your own.
It doesn't sound like much but on the end of a long mast it makes a difference. I attached a 1.2 kg weight to my mast tip and tried stepping and it wasn't comfortable. It's do-able but not pleasant. I felt like I was more likely to drop the whole thing.
So before you buy try the weight test.
I just tie a 5 litre (1.3 Gallon) plastic container to the halyard and run that up with the sail. I haven't "capsized in action" but in practice capsizes my mast never wanted to go turtle.