Weight, nice and light,
Strength, even with its lighter weight, it still has good, cross loading and open gate strength.
I got a few of these carbs, and they havent let me down yet, nice smooth gate action even after loading.
The design allows the rope to sit nicly in either end of the carb, ensuring that you dont accidently cross load it. The gate opening space is also excellent.
However the carb is small-ish compaired to other you can buy so can make it a little fiddly if you are wanting to put a few knots onto it, but if thats your problem then just buy a bigger carb.
Good bit of gear, worthy of addition to any ones rack.