Atlas V:
Total launches 14
[For breakdown by variant, see text]
Successes 13
Partial failures 1 (401)[1]
http://en.wikipedia.org/wiki/Atlas_V

Delta IV (Delta 9000)
Total launches 8
Medium: 3
Medium+ (4,2): 3
Heavy: 2

Successes 7
Medium: 3
Medium+ (4,2): 3
Heavy: 1
Partial failures 1 (Heavy)
http://en.wikipedia.org/wiki/Delta_IV

And as Rand states:
Griffin said in 2003:
"The Atlas 5 and Delta 4 EELVs, he noted, have a specified design reliability of 98 percent, in line with experience with the premier expendable vehicles to date. If such a vehicle was used to launch a crewed spacecraft equipped with an escape system of just 90 percent reliability, he noted, the combined system would have a 1-in-500 chance of a fatal accident, “substantially better than for the Shuttle.” "
http://www.transterrestrial.com/

So, it looks like the "design reliability" has shown it's itself to be fairly accurate in actual flights.
Have these launcher have another 10 to 20 flights and they could be turn out as safe as the Shuttle without including the abort option- which makes it safer even at this point.