Thanks - I did mean both pastes 
I used Thermalright Odyssey 1.5mm, so the former. It was left over from replacing the thermal pads on my GPU (thanks NVIDIA for cheaping out).
At 1.5mm this pad is objectively bad for CPU use; the fact that it was viable at all has made me start looking to get something more performant. Use cases would be quick-swap type testing, and systems I expect to make changes to in 6-18 months (low to medium TDPs).
Agreed cost is extortionate compared to paste; don't expect thermal transfer to match thermal paste but don't agree it's terrible, and not sure I agree with the other parts.
Gamers Nexus did some videos (watched them after your post, to improve my understanding). The numbers were better than I expected:
[SPOILER="WTH are these charts showing"]The chart on the left shows the Grizzly Hydronaut paste/IC Diamond pad delta; so e.g. at 95W you're looking at a ~1.2°C diff, at 150W you're looking at 2.21°C for a decently flat cooler and 2.88°C for an unlevel cooler.
Chart on the right is delta over ambient, because there wasn't one between the pads v paste. The absolute value doesn't really matter, more the difference between the methods; e.g. at 150W the (yellow) IC Diamond is worst, with the (red) Grizzly Carbonaut pad 1.02°C cooler, and the (blue) Grizzly Hydronaut paste 2.21°C cooler than the IC Diamond pad (the first chart is nicer at it just shows the relevant 2.21°C at 150W, but does not include the numbers for Grizzly's Carbonaut)
[/SPOILER]
