Object 704

"Developed in 1945 on the basis of the IS-2 and IS-3 vehicles, under the supervision of Joseph Kotin. One of the distinctive features was the balanced slope angle of armor plates. Passed trials successfully, but never entered service." The Object 704 is a Soviet tier 9 tank destroyer.

Pros

 * High damage per shot and penetration.
 * Numerous armor hardpoints/spaced armor voids.
 * Superior acceleration and turning than the ISU-152.
 * Exceptional camouflage values.

Cons

 * Improved frontal armor is still unreliable, will be shredded by high pen ammo.
 * Long aim time and below average accuracy.
 * Poor traverse speed.
 * Wider horizontal profile, though lower vertical, when compared to the ISU-152.
 * Lower speed limit compared to the ISU-152.
 * High priority target, will attract an overwhelming amount of attention if spotted.

The Object 704 is, for the most part, a direct upgrade to the ISU-152. Everything you learned from the ISU-152 you will make use of in the 704, and you get some pros and lose some cons.

The best upgrade you get is your gun. The BL-10 is a much more superior gun than the D-4S top gun on the ISU-152. Boasting better accuracy, aim time, and penetration (from 260mm to a whopping 286mm), it is much easier to play the role of a sniper in this tank destroyer.

Secondly, the armor is a surprising upgrade. On paper, it only has 120mm of armor, but it is very well sloped. The sides of the front are also spaced armor, and landing a shot there does no damage. As an even bigger plus, the gun mantlet is larger than on the ISU, making half of this tank's front effectively immune to damage.

While it's not designed as such or treated by many as if it can, being an assault gun (peek-a-booming, getting in close, etc.) is very much a viable play-style under the right circumstances. This is a big difference from the ISU, which lacks the armor, modicum of agility, and hitpoints to pull this off. However, a sniping-oriented play-style is still very much viable with the excellent camouflage, like in the ISU, and the area denial inherent to that play-style can be highly effective, as no one at any tier wants to be the first to round a corner and get hit by 750 alpha damage.

However, some things are traded from the ISU. Firstly, the tank is wider to each side and is more prone to getting hit. The Object 704 also looses 4 km/h top speed, which effectively makes the tank slower than the ISU in long-distance relocation.