If you don't compare ropes by there respective specs then what do you compare them by, horror stories?
Number one for me is horror stories. Believe it or not, there are some BAD ropes out there. And the specs won't help you filter them out.
Longevity, handling, and price are numbers two three and four on my priority list. And only experience using the rope will help - there are no specs worth a damn, except maybe sheath %, to shed light on those.
Number five for me is the only spec I look at - impact force. And though Beal has been head and shoulders above the competition on that note for as long as I've been climbing, I have yet to buy a Beal rope. Though I may some day.
I would trust UIAA ratings way before i trust any crag story or any single person.
That's fine, so long as the UIAA ratings are telling you something useful.
You wouldn't pay 50$ more for 4 more UIAA falls?