Browse the picture thead here, on the Tiberius Forums, and mcb and you'll see a few who have put on the mock magazines. I'm not certain they are the model you linked, but they due look pretty good.
Personally, I'm more a form should follow function guy so I'd rather have a bi-pod, vert grip, and or a Magpul AFG2 (angled fore grip) up there. But I can't deny the mock assault rifle mags look nice.
Actually I think my favorite mock mag on a Tiberius was actually mounted on a custom stock. Made it look like a bull-pup style sniper rifle. Kinda looked like a Type-88. (http://www.militaryfactory.com/small...allarms_id=258