They were “independent” countries, so they had more freedom. Of course, no travel to the West, lots of bullshit, but still free. Countries incorporated in Soviet Union were blindly following orders from Moscow.

More strict version of socialism. E.g. private business was flat-out outlawed in USSR until the very end. Other eastern bloc countries had more lax rules.

On top of that, USSR was actively trying to incorporate newly acquired territories and assimilate non-Russian people to build the Soviet Man. Significant part of population wasn't very happy about it. Meanwhile satellite countries were busy building nation states and had less internal struggle.

IIRC, Soviet budget was much more military-oriented as well. More money towards budding regimes in Africa, Asia and South America too. Meanwhile satellite countries in eastern bloc were neutral or even received some resources from Moscow.

There was more economical freedom in Eastern European countries compared to those incorporated in Soviet empire. At least small private initiative was somewhat tolerated. Also, in countries like Poland communists weren't able to completely suppress religious attachments of populace. They had to accept the existence of alternative, competing moral, and cultural values, and it had the general effect of less-controlled cultural, and private space. Very unlike the strict USSR model where everything had to be in line with central-planned norms.

Parts of Poland were under Prussian rule and had some accumulation of industry, infrastructure and expertise. Russia was an agrarian country before communism.