The second best Tier X TD weapon
The 152 mm gun is deceptively short, yet it is probably the most dangerous non-autoloader/non-SPG gun in the game. The M64 has the highest penetration in the game paired with great accuracy. This is a great step forward compared to the BL-10 of the Object 704 which has a legendary “temper”. You had to sacrifice a goat every time you started to play to keep the spirits guiding the 152 mm projectiles to the target happy. The new gun has “those games”, but nothing extraordinary, the new American 155 mm has weird shots as well. The M64 shoots straight, mostly.
The great penetration is one thing, you still have to aim at the accustomed weak spots to maximize your chances. The Tier X TDs have all great penetration, accuracy and aim time is more important. Especially the latter is, but the M64 is quite good for such a huge gun by Russian standards. Basically, the vanilla M64 aims like the 122 mm of the Su-100 with gun laying drive, but I still recommend the faster-aiming equipment. It not only helps to track any moving target but it decreases your exposure time, and as I told, Object 268s can fight better at close range than 704s.
One more reason to play less static
You get better mobility and gun than the 704, but there is a price. The horizontal (and the vertical) movement of the gun is very limited, poor by any standard. You better take the initiative and rush your opponents instead of ambushing, because the tracking of moving targets can be very problematic at shorter range. The enemy tanks move outside the limited arch of your gun constantly, and then you have to move your hull and restart the aiming procedure. If you use camonet, the movement of the hull will nullify its bonus.
Rammer-ventilation-gun laying drive
Again, gun-laying drive helps some, but I wouldn’t use stand-off equipment on the 268. I would go for maximizing the general performance, the accuracy and reload time, especially the shortest possible aim time. The damage output is something the Object 268 is very good at. It has the highest DPM of Tier X TDs, the 268 fires about 20 percent faster than the benchmark T110E4. It outdamages even the fast-firing T110E5!