CX4 with Custom DuraCoat Paint
Click for larger picture (Left side view)

FACTS
 Brand  
 MakeBeretta
 ModelCX4 Storm
 Method of operation  
 Semi AutomaticBlowback
 Trigger1 Stage
 Feeding SystemDouble Stack box magazine
 Technical 
 Weight5.67 pounds
 Width2.5"
 Overall Length29.7"
 Barrel Length16.6"
 Functionality
 Bolt position when firedClosed
 Bolt upon last round firedOpen
 Magazine capacity20 rounds
 Decocking or Dry fireDry Fire
 Field Stripping  
 Tools requiredNo
 Small parts retained or looseLoose
 Ammunition  
 Caliber9mm
 Energy @ Muzzle~358
 Velocity @ Muzzle~1,140
 Grains115
CX4 with Custom DuraCoat Paint Rear
Click for larger picture  (right side rear view)
Opinions
 Method of operation  
 Blowback is very reliable and I have shot well over 1,000 rounds through this gun without issue.  There is a lot of plastic in this gun (even in the world of plastic guns there is a lot) the hammer and guide rod are plastic is this one. However I have never had any issues and rust shouldn't be an issue.
 Functionality  
 PriceFair
 AvailabilityGood
 Modularity / AccessoriesVery Good
 AccuracyVery Good
 ReliabilityGood
 Ease of field Stripping  
 Very easy to field strip as absolutely no tools are required.  It can also be made reversible without tools. 
 Ergonomics  
 The cocking lever, and ejection port can easily swap side or you can mix and match.  For example I run the cocking lever on the left however some right handed people may want it on the right a lot of people have bought an extra one and run them on both sides. 
The following items are reversible:
1 - Safety
2 - Magazine release
3 - Cocking handle
4 - Ejector
 Sighting System (Optics)  
 Iron sight backup don’t interfere with red dot
Optics selection
Co-Location
Sight radius 12.9  and fold flat and 2 aspects (long range and short range).
I use a Trijicon TriPower on a quick disconnect 1/2" raiser that has been custom painted to match the gun and it works effortlessly.
 Ammunition  
 PriceFair
 AvailabilityVery Avialble
 PunchFair
 Links  
 http://www.cx4storm.com/
 http://www.beretta-cx4-accessories.com
 http://www.spectergear.com/
 http://www.streamlight.com/
 http://www.trijicon.com
 http://en.wikipedia.org/wiki/Cx4_Storm
CX4 with Custom DuraCoat Paint Trijicon
Click for larger picture
(Trijicon TriPower)

 My ramblings (Over all feelings; Why this Gun; is it worth it):

 I have added a lot of stuff to this little gun to help round it out:
  Specter Gear SOP Sling BK w/ TRB & ERB Releases
  Specter Gear Magazine Pouch (3-20rd magazine capacity)
  Beretta CX4 Top Accessory Rail Kit
  Beretta CX4 Bottom & Side Acc Rail Kit
  Beretta CX4 Soft Case Black
  Beretta CX4 9mm (92) 20RD Hi-Cap Mag w/ Spacer
  Beretta CX4 Storm Tactical Sling Swivel 
  Insight M3 Tactical Light Black
  Trijicon Tri-Power sight (requires 1/2" raiser) I used the quick release AimPoint that has a consistent torque lever.
Its a very fun gun to shoot and I have never had any issue with this gun.  I don't particularly like how the top rail is mounted but I believe they have fixed this in the later models.  In comparing it to other firearms I have often told people that they may like it more than a PS90 or an HKUSC because dollar per dollar its very hard to beat and I have fired over 1,000 rounds through this firearm without issue.

CX4 with Custom DuraCoat Paint Lower
Click for larger picture  (Bottom front)

CX4 with Custom DuraCoat Paint M3 Light
Click for larger picture (M3 Light)


CX4 with Custom DuraCoat Paint Stock
Click for larger picture (Rear Stock)

Slow shot target 25 yrds
Click for larger picture (Slow shooting)

Fast shot target 25 yards
Click for larger picture (Rapid Shooting)