is it worth splashing the cash on them? or can i save some pennies by buying cheaper models, i.e a pg950 vs a pg980 casettes and a pc-951 vs pc-991.

I always use Dura-Ace chains, they're just better. Cassettes, I'm not to fussed on.

Better quality cassettes seem to be lighter but not sure they last much longer overall


I tend to buy mid priced SRAM cahins which work well for me

Personally I think Shimano chains are crap, I'd sooner have a mid range SRAM than a top of the line Shimano.

I wouldn't have said there's much real difference, I'd save your cash if you're not bothered.