It looks like you'll need to lower your AC to below freezing in order to unlock the full potential of the i9 chip due to thermal throttling. Otherwise, in normal room temperatures, this new model performs slower than a 2017 MBP with an i7 chip. At least when using Premiere Pro. Perhaps Apple is pushing more editors towards FCPX this way?
https://www.macrumors.com/2018/07/17/core-i9-chip-macbook-pro-throttling/
While this isn't good news, this issue isn't limited to Macs. Intel has a lot of work to do in the area of thermal throttling and it doesn’t look like things are generally much better on the PC side. The Youtube reviewer referenced in the Macrumors article recently posted a video that I have linked below about the new XPS 15 (9570) titled “The Problem Persists”, in which he laments that the Dell suffers from similar thermal throttling issues when kitted with the i9-8950HK. Even Dell's Alienware brand is apparently having issues.
The problem appears to have to do with architecture of Intel's current processors. According to the NotebookCheck article linked below the "i9-8950HK has the ability to boost one core to 4.8 GHz (+200 MHz) as long as the CPU temperature is below 50°C. Multiple cores can be boosted +100 MHz below 50°C." Apparently, when doing processor intensive work it's pretty hard to keep 6 cores below 50°C. In his Dell video Lee says these thermal issues make it hard to build a notebook that looks like a notebook computer.
This thermal throttling issue probably helps explain why Apple didn't include a more powerful GPU in this iteration of the MacBook Pro. The GPU also generates heat which would likely result in more CPU throttling.
This throttling problem is apparently an issue across Intel's product line. Last month at Computex Intel demoed a screaming 28-core system running at 5 GHz. What they didn't reveal at the time was that system was overclocked and required a industrial chiller the size of dorm room refrigerator. It was a little sneaky and Anandtech wasn't happy about Intel not being more forthcoming.
AMD has Intel on the run, so maybe they feel desperate times call for desperate measures. Hopefully this throttling issue will get better when Intel finally moves to their delayed 10nm process. Even better maybe someone will come up with some brand new cooling tech.
For me support for 32gigs of RAM, hardware mitigations for Meltdown and Spectre, a better keyboard (hopefully), and other improvement make this model a likely good fit. I'm going to give it through next week to make sure no show stoppers come up, but it still looks like a buy to me.
https://www.youtube.com/watch?v=18PA3WFFuAo
https://www.notebookcheck.net/Intel-Core-i9-8950HK-SoC.279270.0.html
http://forum.notebookreview.com/thr...-i9-8950hk-gtx-1080-but-still-like-it.816635/
https://www.anandtech.com/show/12932/intel-confirms-some-details-about-28core-5-ghz-demonstration