"does your manager think you're good" which is it's own giant can of worms." I have bad news. Unfortunately if your manager does not think you're good, literal

"does your manager think you're good" which is it's own giant can of worms." I have bad news. Unfortunately if your manager does not think you're good, literally nothing else you're going to do will matter, no matter what metrics say in either direction. If your manager does not think you're good, you should leave immediately unless you have some trump card in the form of a higher-up manager who does think you're good. It's the only exception (and barely an exception at that). So, short of that universal caveat, what system is better? I've said this and I'll say it again: EMs should have unilateral power over their reports performance designations. They already basically do, and the delta wherein they don't is by far abused for evil more than it is for good. So just close the gap.