The Object 705 is a great vehicle if you want a glimpse of what you can expect at Tier X. Compared to the IS-M there are a couple of differences we're going to highlight throughout the guide, and all in all, this heavy is more than a worthy successor to the preceding vehicle.
Coming from the IS-M, the survivability saw some massive improvements generally but there are new weaknesses you need to pay attention to. The frontal plate became much tougher but now there is a bigger difference in effective thickness between upper and lower plate compared to the previous vehicle, meaning that the lower plate is the main weak spot of the Object 705 – try to hide it, if possible. The upper plate became much stronger and can withstand a lot of punishment.
The side armour is now divided into two main zones, the upper and lower one. While the upper part comes with extra protection (spaced armour), the lower zone is barely protected and is actually weaker than the IS-M's. You need to be more careful when you side-scrape, as with the Object 705 it's more difficult to pull off. If you side-scrape correctly, you'll only show the upper stronger part, as it's more on the outside than the weak zone.
The 130 mm S-70 packs a bigger punch than most heavies on this tier and features good penetration values, but keep in mind that this is a Soviet gun we're talking about. The accuracy is really low and it takes a long time to aim. The only way to counter this is engaging in close-combat, where it doesn't matter as much. Always check who you're up against and then decide how you want to proceed – the Object 705 can be used both for offence and defence.
As mentioned, the gun accuracy is very low, so it makes more sense to make the gun as reliable as possible. Additionally, the potential damage per minute is rising, which always comes in handy.
Standard choice of crew skills. All these will both increase your gun performance and the survivability of your vehicle. Of course, having a more experienced crew will be more beneficial and all of these skills and perks above make a noticeable difference.