Ahh... I know that impulse to find similarities between what you dislike - I do it myself.

But in this case you
are wrong, the economic systems of the "west" and the "soviet block" were not just the same thing dressed up with different speech.
There were similarities, and indeed there were comparable classes in each block. The "managerial class" in the capitalist block had its counterpart in the "bureaucratic class" in the soviet block. Galbraith made a persuasive argument for such institutional similarities still when the Cold War was in full swing and to do it was heretical in either side - but he was always one to write those simple but inconvenient truths that
you just don't admit when you are a member of respectable circles!
But what about the capitalist class proper, the "rentier class"? Did the rentiers of the capitalist block had their counterpart in the
nomenklatura? Djilas complained that they did, but the way I see it, it really wasn't the same thing. The
nomenklatura were politicians on the active, akin to western politicians on the active and/or administrators. It was part of that "bureaucratic class" which was a counterpart to the western "managerial class". The "rentier class" typical of capitalism had been successfully eliminated (or, more correctly, diluted - one of the goals of socialism) in the soviet block.
That was why it was so hated and feared by the members of that class in the capitalism block. It
wasn't just posturing.
The difference between having a rentier class which is allowed to gradually concentrate wealth (wealth begets more wealth, and rents from wealth accumulate with a compound effect), or having what has become fashionable to call "state capitalism" (I really would like to know who coined the term) where the proceeds from any "rents" (profits) are either generally redistributed through state services or reinvested, has big institutional consequences! Big social consequences too. If it didn't then the crassest of capitalism of the most benign of social-democracies would be similar, something which the people forced to live under one or the other have very often (and sometimes violently) rejected by demanding changes from one to the other.
It would be worth, it seems to me, do discuss what "state capitalism" is. Not only because that has by far been the most often used alternative to "capitalism" but also because the term itself is, I suspect, politically loaded towards pretending that it is no different from capitalism. Which is a rather... bold claim.