T___A

I believe the top is the air filtration system the bottom is the engine cooling system.

279 roadwheel

I believe the top is the air filtration system the bottom is the engine cooling system.

279 roadwheel

Yeah but that's mostly because of the timing of the SU-122-54 more than anything. Omsk didn't trail blaze on anything mentioned. The IS-7 has everything you mentioned and more and that came in 1947. 
 
 
They didn't which is why only 77 were made. The problem is that a 122mm spg is fundamentally nonsensical after 1944.
 
Come on, the SU-100P is more relevant to Soviet tank technology development than the SU-122-54.

You, suitcase, Black Volga, Magadan

 

Both A.G. Karpenko and Baryatinsky say that the Object 268 already had a tray type auto-loader which is why they were able to get away with a four man crew.
 
 
Object 261 is really fucking obscure. What many people don't realize is that it actually three different designs and the wooden model that is everywhere on the internet isn't actually the Object 261:
 
 
Object 263 is even more obscure. The only person who has written at length on the Object 263 is A.G. Karpenko  who says that the Object 263 uses parts from both the IS-8 and IS-7.

Afghanistan
 

Afghanistan
 

Afghanistan
 

L M A O
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Chelyabinsk, spring 1947:

Pictured, the Union being awesome:

Chelyabinsk, spring 1947:

Chelyabinsk, spring 1947:

Object 770:

Politics mainly. The Object 277/8 and Object 770 were designed on the orders of the Sovet Ministrov so every other design was unsolicited and for some reason the Soviets had weird hangups about unsolicited designs. Also the Object 777 only had a manually loaded M-62 which was not gonna fly. The Soviets right after the war decided  that the next generation of heavy tanks was going to a use an auto-loaded 130mm. The only reason the IS-4 and T-10 didn't get the 130mm was they were meant to be quick and easy replacements for the disaster that was the IS-3

I get the impression that the sentiment you're echoing is mostly a western thing. Every contemporary source I've seen on the IS-3 has been negative. They just didn't like it. For good reason: There was just a lot of problems with it. At one point they had to return literally every IS-3 to the factory to fix the welding which was falling apart. Notice that their response  to the IS-3's problem wasn't "wait for the IS-7" it was "oh my god resurrect that heavy tank program we canceled years ago and get it ASAP". The IS-3 was that bad. The problem with the IS-4 was just weight, otherwise they were enthused with it. To the point that when the designing of the T-10 was ordered the government demanded IS-3 shape and size but with IS-4 technology. And I would say the result was pretty good.

If Khrushchev was right it wasn't because of any foresight on his part. The man clearly had no aptitude and knowledge for both armored warfare and tank design. I'm not sure if you're familiar with why the T-62 has the 115 but he was involved and the whole affair was dumb.
 
If they weren't canceled either the Object 277/8 Object 770 or would've been produced*. Probably with the 140mm smoothbore. Maybe the Object 292 would also be produced as a hold over until 277/8 or 770 gets rolling. After that its impossible to say the if the later designs would be worthwhile. I think pure institutional inertia from the SA would keep heavy tanks going at least until the collapse of the USSR. Again I don't know if  the later designs would be good and therefore worthwhile. All the heavy tanks designers threw in the towel after the decision but I don't know what happened to their protégés after the infamous order. So I don't know if they were any good. I presume they kept working in the industry. 
 
 
*Probably with the name T-11 since it would've been the 11th heavy tank produced by the Soviet Union. 

Object 770:

Since flechettes have fins is there any reason SPIW, AAI's ACR, and Steyr's ACR all have rifling? The Steyr IWS 2000 also fires a flechette yet it is smooth-bore unlike other flechette firing weapon.