Russia has historically used Post Revolution Iran as bargaining chip against West. Fighter jet deal cancellation in 1991, S-300 fiasco, Nuclear sanctions, Caspian Sea water scandal, all pointed to the disbalance relations. Recent leakages are pointing towards Putin selling Iran to US-Israel in Syria. I am not against Russia by any means but IRI should have acted smart with Moscow which they did not.
For a Chinese person to not know the history of bordering Eurasia is surprising but here it is. Iran and Russia have been bitter enemies for centuries, Russia took entire Caucasus from Iran including chunks of Iran itself by force not too long ago. Armenia, Georgia, Azerbaijan etc were provinces of Iran, same people, same genetics and history yet they were carved out of Iran by force. Post WWII, USSR again tried to carve out Soviet republics out of North western Iran but had to back out due to US pressure. Shah led Iran was an armed to teeth problem for USSR (Read Operation Dark Gene). Revolution in Iran ended this rivalry but Russia never treated Iran as an ally.
Iranian government is a Islamo-Marxist revolutionary theocracy that cares for their ideas by staying in power, more than interests of Iranian nation.
Given our different cultural backgrounds, it's not appropriate for us to delve into in-depth discussions about historical and political issues. Furthermore, this is a military thread, so let's get back to the topic.
SU-35S is not some core technology. Its just another variant of SU-27 from 1977. Its literal designation was SU-27M before they started to call it SU-35S. It has no AESA radar, no light weight long ranged BVR like meteor, it has no ALBM package or Stealth tech. Yes for IRIAF its a must to have considering Iranian government killed the force deliberately. SU-57 can be called the real cutting edge tech though.
Regardless of how you evaluate the Su-35S, the fact is that Iran has officially purchased it. This is the best option available to Iran under its current circumstances.
Unfortunately, you don't have any other better options.
The Su-57E is not suitable for direct entry into service with the Iranian Air Force.
------ We have already discussed this issue in depth in another thread. Any 5th-generation fighter jet requires a corresponding combination of 4th-4.5th-generation fighter jets as partners and guides. You cannot skip these 4th-4.5th-generation fighter jets and directly introduce 5th-generation fighter jets.
------ You need to first introduce the corresponding 4th-4.5th-generation fighter jets and perfect the corresponding air combat system before considering introducing the corresponding 5th-generation fighter jets. That is, if Iran wants to buy the Chinese J-35 fighter jet, it must first purchase the Chinese J-10CE fighter jet (other Chinese 4.5th-generation fighter jets are also acceptable) and other supporting air combat systems. This is a prerequisite.
Regardless of how you evaluate the Su-35S fighter jet, it is certainly far more advanced than any fighter jet currently in the Iranian Air Force.
Although most people believe that the J-10CE has a much more advanced avionics system than the Su-35S, this is only one aspect of fighter jet evaluation. Based on the operating environment in Iran, the Su-35S, a heavy fighter, is more suitable than the J-10CE, a medium fighter. Furthermore, the J-10CE fighter is more dependent on an integrated air combat system, while the Su-35S is less dependent on such a system.
Based on these realities, I believe that the Su-35S is more suitable for the current Iranian Air Force than the J-10CE.
Russia is currently facing both internal and external difficulties. They urgently need to expand broader international cooperation. When Russians are in distress, they are willing to negotiate on any terms, without any bottom line. (You can recall what Russia sold off during the collapse of the Soviet Union...)
Therefore, now is the best time for Iran to negotiate a technology transfer agreement for the Su-35S with Russia. Once Russia's situation improves, their bargaining power will increase.
Of course, what Iran ultimately obtains depends on the negotiating skills of the Iranians. More importantly, it depends on whether the Iranians put in sufficient effort through these collaborations.
India imported the complete Su-30MKI technology from Russia...... To this day, India is still unable to independently manufacture the Su-30MKI.
China imported Su-27 assembly and maintenance technology from Russia...... Today......
So, if Iran were to acquire the complete Su-35S technology package, to what extent could Iran ultimately develop its capabilities? This would entirely depend on Iran itself, not Russia.