Whats the consensus on the Solder? Has it sorted out the temps?
Gamers nexus tested solder tim vs hydronaut under the ihs which should be better than whatever intel was using and found the solder TIM performed better than the hydronaut but not by much.
So vs a premium paste it isn't a huge improvement.
Der8auer delidded several and found that the die silicon is now thicker and as a result doesn't dissapate heat as effectively as it could. He reasoned that it was likely a thicker die was needed for the STIM to be effective. Also that thicker solder was needed after trying to resolder a chip with a thinner layer which didnt work.
He found that liquid metal, plus removing the solder and lapping the die to reduce its height results in considerable improvement in heat dissapation over the STIM implementation.
Reviews have been mixed on temps. Some people are seeing easy overclocks on standard cooling like air or aio coolers while others are seeing their chips run hotter than tindaloo fart, even with custom liquid loops.
All in all it seems like the STIM is better than the previous compound but not by a huge amount. If you get a poor chip then the extra cores make heat a real problem and overclocking a pita.
On the other hand, getting 5ghz on all cores without delidding, or even 5.1, 5.2 is possible with an aio. It really seems to depend on whether you win the silicon lottery or not.
For reference, gamersnexus hit 5.2 on a x62 kraken i believe, and when asked in the livestream if an x72 and 9900k should be able to hit 5ghz he said 'yes, should be trivial.'
All in all it's been a mixed bag of reviews showing that when overclocked and under unrealistic loads like stress testing the cpu is hot.
But because overclocking doesnt seem to be difficult for every sample I'm willing to bet the quality of the cpu plays a larger role than STIM in temps.
TLDR: It has improved things but the CPU can run hot depending on the load, clocks and quality of the silicon.