Sidious has already replicated every single showing Plagueis has done in lightsaber combat (except for beating Venamis, but unless you think he's incapable of that for some reason, I'd say he pulls it off too), and has comparable showings in physical augmentation. He also rarely trained after this, so his skill showings from later incarnations could also be attributed to this Palpatine. Not sure who wins; probably a stalemate.
For Force, Sidious, eight years before TPM, already pulled off the unbalancing feat alongside Plagueis. It should be noted the text described neither Sith doing more work than the other, indicating equality. It's likely Sidious surpassed Plagueis in the eight years following this. He's also stated to know every single Force power Plagueis knows.
For feats, he has tanked Plagueis' Maladian-pulverizing Force wave to the face. While it is true Plagueis wasn't in peak condition, it is also equally true Sidious didn't even flinch.
I might support Sidious for Force and all-out.