I talked to James who had displayed the magazine at shot show, he said the interest in this magazine was overwhelming, and there was a lot of mention about the IAR program. They are sending them out to several major players for evaluations and if they fit the bill they will be using them in the field. The actual exterior of the magazine he said will probably be covered in grip tape (like that used on a skate board) for quick maneuvering out of a pouch and for reliable handling.
True BUT the program was almost cancelled due to the point that 30 (boxed) rounds is not 200 (belted) and that was a major selling feature to keep the M249 in the SAW role vs fielding the IAR in the AR role. The avilability of a reliable low profile hi-cap magazine would have reduced that point as an obstacle AND more importantly increased the capability of the M27 in specific roles where you want and need a higher continuous volume of fire w/o reload (ambush/counter ambush, break contact, up against an AK/RPK with a 75 round AK drum!, etc.).
The beauty of the drum magazine like this one (or the HK G8 drum) is that they work well compared to dual drums (Beta mags) and the are not so long like the Surefire stick mags that you cannot assume a proper prone position with the weapon upright and not tilted. These long Surefire stick mags are going to get trashed in hard infantry use as their length becomes the very lever that damages the mag and weapon possibly when the gunner falls on the mag or jams it into a door or window sill during entry/movement.
If this 50-rd round drum mag is robust and reliable I predict the Marines will purchase and field some very quickly for eval. The M27 can easily handle the sustained rate of fire (up to 75 rpm) and cyclic rate of the 50 round capacity. Maybe the gunner carries one for initial engagements and then 30 round stick mags after that.