I am about at 2500 miles on this chain ridden in gritty conditions but cleaned often an doesn't appear to be strech, but I am thinking of getting a new chain every 2500 miles.

Which is better? There is only about a $4 difference and I heard that maybe the 105 ar 5700 is more durable than the Ultegra 6701.

TIA

The only way the 6701 chain will be significantly longer lasting is if you take better care of it then the 5700. Andy.

+1,

Discounting low end chains which aren't made with the best materials, the difference in chain life best to worst is something less than 20%. So spending a premium price may get you more chain life, but the improvement will be less that the cost difference.

IME the way to get the most chain miles per buck is to buy mid level chains (the ones just below those with fancy plating, punched links or hollow pins. Then take decent care of them.

Based on their place in Shimano's pecking order, the Ultegra 6701 should be more durable but in real-world use the difference should be minimal. Once you get above department store stuff, cleanliness and lube frequency make far more difference than model.

I buy the cheapest Sram or KMC chains and maintain them. I remove them every 750 to 800 miles and clean them in an ultrasonic cleaner.
The tourer's chain is almost worn out at 18,335 miles and the road is going good at 11,894.

Did you measure your chain? You may be replacing it before it's worn out. I prefer the KMC 10.93 chains to Shimano. Cheaper, lasts as long or longer, includes a re-usable link and shifts just the same.

Thanks all for the input!