Yep. AS5 is solidly mediocre. Right in the middle between liquid metals and toothpaste. MX-4 will drop you maybe 1-2°C at best. And only at loads. Tims like Noctua NT-H1, Gelid Extreme 3, Phanteks, Thermal Grizzly Kryonaut are slightly better, you might see 3-4°C, but mainly those pastes are chosen for ease of use more than actual performance (except for benchmark chasers). Those pastes do not have a cure time, do not dry out and consequently never need repaste if done right. AS5 does have a cure time, roughly 200 heat cycles, that's from cold to very hot and back. Then it's dry. No worries. Pastes do not transfer heat, they are only the medium that holds the silicates, diamond dust, minerals etc that do transfer heat. So a dry paste works just the same as a wet paste. Until you break that seal. Can be a slight bump, vibrations, bounce the heatsink, move the heatsink while cleaning the fan. Doesn't take much. Almost exactly like hot-glue, works great until you break the seal, then it will never stick back. That's when temps go nuts and you need to repaste. For the average user, that's @ every 2 years or so, for heavy users with fastidious cleaning habits it can be every 6 months to a year. It's the only real bad part about AS5, once it cures, do not touch/bounce/vibrate the heatsink, and the bigger/heavier the heatsink, easier it is to mess up and break that seal.