I would say that the Below are the reasons why.
Especially the items in Red.
Capabilities:
- Rapid fire/rapid reload, suppressed sniper rifle
- Exceeds rate-of-fire and lethality of M24 SWS
- Reduced weight
- Primarily anti-personnel at ranges equal to or greater than M24
- Includes enhanced sniper spotting scope system
- Folding detachable bipod
- 5-,10-, and 20-round capacity detachable magazines
- Barrel life greater than 5,000 rounds
- Variable power day optic scope
- Detachable weapon suppressor
- Hard transportation/storage case
- Integrated Mil-STD 1913 Rail
- Deployment and cleaning kits
MK11 / SR 25 Sniper Rifle / XM110 7.62mm Semi-Automatic Sniper System (SASS)#
As you can see...it ain't a bad looking critter
But I don't see how it could possibly be "better than the Barrett".
I'm sorry, but .50 cal trumps 7.62 all day long.