As of Update 9.5, the Acrid uses a different reload animation than other pistols.
As of Update 10.3, the poison mixture in the barrel is affected by your energy color, and the tiny explosion effect on needle impact. Note that the explosion effect is purely cosmetic.
The pinpoint accuracy introduced in 10.4 was most likely due to the change in the Magnum Force mod, if the Acrid had kept it's slight sway in bolts, this mod would have made the acrid's bolts spread out like a shotgun.
Oddly, it will apply poison damage with the poison symbol each time, without the need to proc, unlike other elemental dealing weapons like the Ignis, which requires it to hit the proc chance in order to deal a fire stun effect.
Semi-automatic firing can be countered by simply adding an alternative way of firing on 'scroll up' or 'scroll down' through the key binding customization.
Before Update 10, Saryn + Mire + Torid + Acrid would give you the only loadout consisting solely of poison.
Or use the Dual Ichors in place of the Mire for more damage, and doing pure poison damage vs. the blade damage of the Mire.
The Acrid is physically the largest handgun in Warframe.