The CMP has the fastest reload time of any SMG (very nearly the same speed as a pistol), a high fire rate, and good total ammo. The downside to the high fire rate, though, is unpredictable recoil, which it shares with the Mark 10. It will often recoil to the sides and downwards. This can make it difficult to use for someone who's not used to this unpredictability.
All these things, combined with the slightly obstructive iron sight, make the CMP strictly a close-range weapon. With certain attachments, you can reduce the recoil to allow it to perform better at medium-range situations. A skilled user can absolutely devastate groups of weak enemies when the time is right. With the necessary attachments, the CMP becomes a good all-around weapon for any heist, having the high RoF of the Mark 10, the ammo pool of the Blaster 9mm, damage of the Para, and accuracy of the Kobus 90.
*The LED Combo is based on the Leapers, Inc. UTG LED Weapon light and Laser. **Although the main flashlight has a toggle switch, the laser sight component of the LED Combo is pressure-activated, meaning the laser will stay on as long as the pressure switch is depressed. This switch is not placed where it should be, however (on foregrips, magazine wells, etc...) and is instead ziptied to the main taclight, leaving no plausible mean for the user to toggle it without awkwardly moving their off hand off the weapon and gripping the attachment itself.
*Upon release, the default reticle of this sight was a chevron instead of the retail version's red dot. After the release of the Gage Mod Courier DLC, it was reverted to the regular sight's red dot. *It is functionally the same as the standard Military Red Dot Sight, but the sight's casing is tan instead of black with the line "A-10" scrawled on near the adjustment knob. The sticker on the lens cap's interior also says "I <3 Payday" instead of having a picture of an American flag. *This sight was based on the Aimpoint CompM2 optic. While it is portrayed as a high-zoom scope in-game, the CompM2 is actually a reflex sight, meaning it offers no magnification in reality.
The Acough has the greatest zoom in the game for a non-sniper scope. That being said; the high zoom level combined with its bulky sight casing can hamper target acquisition at point blank range, pairing the scope with a laser sight can dramatically alleviate this potential difficulty.
The CMP is based on the Brügger & Thomet MP9-NA3. It can be easily differentiated from the parent weapon by it's lack of a front grip, with an under barrel grip-less rail in it's place. The sideways folding stock and top rail mount featured on the CMP are also parts native to the MP9. Attaching the Skeletal Stock gives it the looks of the MP9-NA4, though a real MP9 is not usually compatible with this part due to the added stock hinge molded into the receiver obstructing the stock's clamps.
The stamping on the left side of the weapon confirms that the CMP is a MP9, though the first letter of the stamping is partially hidden by the rail mount so it is hard to tell which specific model the weapon is. The side rail is also unusually located to the left of the CMP rather than on the right like the real-life MP9.
The CMP lacks a fire-selection dial on its left side, meaning it should not be able to alternate between semi-automatic and fully-automatic fire like depicted in-game, but rather uses an old-model double-stage trigger to produce either single shots or automatic volleys.
The CMP's bolt does not move when the charging handle is racked during a full reload.
"CMP" is most probably a reference to the CMP-150, a similar weapon found in the Nintendo 64 video game Perfect Dark, which in turn was based on Steyr TMP, the parent design of the TP9/MP9.
The CMP's default magazine holds an impossibly large total of 30 rounds, despite being modeled after a 15-round unit. Likewise, its Extended Mag also contains a whopping 12-round addition.
Despite being a machine pistol, the CMP is classified as an SMG in-game.
The CMP is used by every non-SWAT American variant of the Shield unit.
The CMP shares its firing sounds with an unsuppressed SpecOps.
In one of the early builds of PAYDAY 2, FBI Shields used a CMP with a folded stock, a mod unobtainable by the player. This specific CMP can be viewed in the launch trailer of PAYDAY 2, seen from 3:32 - 3:35.
The Stubby Compensator could not be installed to the CMP until Update #10, making it the only weapon that could use some but not all of the standard barrel extensions.