Neither last longer.
The o-rings hold lubrication. They also hold anything that gets inside. Riding offroad gets grime and dirt inside which destroys the o-rings. This causes alot of lateral slop in the chain and the lubrication retention properties are gone.
O-rings were developed to cut the noise of chains in ON-road use. Lubrication is an afterthought.
IMHO o-ring chains work against you when riding off-road. On-road I wouldn't have anything but and o-ring chain.
o-rings last waayyy longer and require almost zero maintenance, the lube stays insie on mine and works as it should, no issues. Lightly rinse it off at wash time and dry it with WD40, no rust, no tight links, works well. Never use lube as that is what attracts the dirt and ruins the o-ring chain.
A standard chain can be made to last. However, it takes a lot of work. For max life you need to basically store the chain in a container submerged in oil. Put it on the bike, ride, clean, and then return to the oil. That gets the crud off the chain and fresh lube in. I'm way too busy with that though. I run a ring chain on my dirt bike. I get a lot of life out of those chains. Usually several years of riding.
Now I have a standard chain on my street bike. It's only a 400cc and runs a 530 chain. Since the chain is pretty lightly loaded due to the small engine I go with an inexpensive non ring chain and replace it often. Since it's not in the dirt it does not accumulate crud anything like a dirt bike. I do a complete clean on the chain a few times before replacement. I remove the chain from the bike and clean completely in a solvent like paint thinner. I might change the solvent a few times so I get every last trace of dirt. Then the chain gets dried completely. I whip up a special blend of grease and a a light solvent like petroleum naptha. It's about 1 part grease and 2 or 3 parts solvent. I dunk the nice clean chain in this brew and work it into the chain. Finally the chain is hung to dry and the excess grease is wiped off.
Be careful with cheapo chains. I never had a failure on my XR until I tried one. The first was a RockyMountain Primary Drive house brand O-ring chain. It broke after a about 6 months. Thank god I was right next to the road. Rocky Mountain actually comped me the chain and I tried one of their house brand X ring chains. It failed in a year. At least that broke right next to my truck. Previous to this I had a RK O-ring chain which lasted five years. I have an RK on my bike and it's got over a year on it with little or no wear.
One thing about ring chains. You need to check them often for damage to the rings. As soon as even a single ring fails the chain is toast and will usually fail pretty quick. My first RM chain fractured a side plate, but my second was due to failed rings.
standard. everything else is just a gimmick... O-rings still need to be cleaned and lubed same goes for x-rings.....
Regardless of price they all last the same.... going on year 2 with my cheapo standard chain.