My standards for Admirals was pretty high, basically = to Akainu because that's how the OG trio was presented. Fujitora was initially a bit of a disappointment for this reason. He never gave me the sense that he is on par with Akainu, but after witnessing Big Mom on WCI and Wano, my standards for top tier had to be lowered. Given the new standard, he's more than ok as she looks far worse than him yet he has been held back by Oda, while she has already gone all out.
Greenbull has some minor hiccups, like I said I was scared for the rest of the top tiers post skip since WCI, however Oda already cemented Greenbull above Big Mom within his first few panels. He's been catching bodies left and right, featwise pound for pound he might be the top 1 in the verse. Oda's kept him humble with his interaction with Shanks, otherwise we'd be having a different convo rn (is Arakami the strongest in the verse type convos). Can't be too disappointed with that.
Kuzan is exactly where I thought he would be, following up on Akainu making the BB pirates run away, he basically replicated that against the Yonkou version of that crew. Oda damn near insinuated Kuzan can solo an entire Yonkou crew with their captain included. I expect Kizaru to be on that exact same level, his portrayal during MF and him casually asking to step in between Big Mom and Kaidou gives me full confidence he's no different.
The biggest takeaway here though is we're near the endgame and Oda still refuses to let the Admirals try, which means they're still far too strong to let loose casually. There's not much room for disappointment, once they have shown all their cards then we can see if they were disappointing or not.