the video rather exaggerates real world test experience so far on other posts with most getting in range 1.5x to 2x improvement but poor old @
f14tomcat getting no change (using an hdd as target - not sure if usb).
However, there is a significant boost.
Actually, a more interesting test was on compressions
source - 35 gb (ignoring temp files) - nvme to nvme
highest compression - 2 mins 45 secs - final size 20 gb
medium compression - 1 mins 58 secs - final size 21 gb
no compression - 58 seconds - final size 35 gb
so for me, comparing against default medium
highest compression - slower and hardly saves anything
no compression - nearly twice as fast (awesome), but uses nearly twice as much space.
Medium gives a good balance between speed and time for me.