From Golf Magazine ClubTest 2012 (April, 2012)

Category: Game-Improvement Irons
Price: $599, steel; $699, graphite

WE TESTED: 4-PW with True Temper TX-Flighted steel shaft; 4-PW with Aldila VS Proto 75 graphite shaft
KEY TECHNOLOGIES: A stainless steel, 54-gram ring (called the “exoskeleton”) in the rear cavity pulls weight away from the face to produce a higher, easier launch and more head stability on off-center hits. The club’s thin face contributes to faster ball speeds.

OUR TESTERS SAY: Sleek, handsome club will appeal to better ballstrikers seeking some help on mis-hits.

PROS
PLAYABILITY: Moderately high, repeating ball flight; good bite on short chips and pitches, a real finesse player around the greens; a shotmaker’s iron.
ACCURACY/FORGIVENESS: Hooks and slices are minimized so shots don’t veer too far off-line; long irons aren’t world-beaters but do maintain a decent level of forgiveness.
DISTANCE CONTROL: Consistent, respectable length on center hits; off-center shots sacrifice a little length but keep you close to the green.
FEEL: Head is easy to locate during the swing and pretty stable through impact; consistent sensation throughout the set.
LOOK: Glossy black finish gives the appearance of a smaller, more classic head; the look of a real player’s club at address, although one can see there’s some assistance in the back cavity.

CONS
Rewards good shots, but a tad less forgiving than typical game-improvement irons; impact feels surprisingly firm on center strikes to some testers and is too hard, even harsh, on mis-hits.

From Golf Magazine (December, 2011)
Designed for: Game improvement
A 54-gram, stainless steel “ekoskeleton” ring is cast into the rear cavity to pull weight away from the clubface and produce higher launch. The “ekoskeleton” also distributes mass toward the heel and toe to stabilize the head through impact. The club’s thin, hot face increases ball speeds—Wilson’s player testing reveals that Ci11 is 3.3 yards longer than the Ci9. Lastly, its black PVD finish gives the appearance of a smaller, sleeker blade.