I would say that yoda was very slightly stronger, the only reason he lost was because he lost the high ground, and unlike anakin hes not gonna jump back up and get chopped in half force lighting'd or what have you. But I think he is stronger because palpatine was pushing thos pods at him, yoda dodges 3 stops 1 (while palpatine is still pushing on it) starts spinning it and fires it back.
Then the force lighting where palpatine is overpowering yoda, then yoda just seems to think forget this and just pushes it all back at palpy with practily no difficulty then they both fell and of course yoda is to low down to continue the battle.
I agree yoda lost because he failed his objective, but the fight itsself was a draw because neither 1 died.