As I understand it the o-ring chain keep more dirt and sand out. Less up keep. If you want to clean and oil your chain after every ride a non o-ring chain will do just fine and last a while.
I bought a RK non o-ring chain for my 300ex and it stretched and wore out real fast. Was not happy with it at all.
If you get the o-ring chain, it still needs to be cleaned and lubed just like any other chain or the dirt and grit will eat the o-rings up in no time. If cleaned and lubed properly, it will last longer than a non o-ring chain, though.
^ i always had trouble keeping my o-ring chain clean enough to not wanna bind up a little,i replaced it with d.i.d non o-ring chain years ago and havent looked back,not a knock on the o-ring chains but ive just come to the conclusion the non o-ring works well for me and at the time i believe it was almost half the price