Well this forum has a large spectrum of opinions so I could see this going from different perspectives depending on the person :shrug:
From hype, ET Madara said his fight with the 5 kage was nothing in comparison to his fight with Hashirama. Dan further hypes the strength of both EMS Madara and Hashirama further. I think Kishi made it clear who the top dogs are in the manga so far.
As for feats goes, he's a master at Mokuton. This can arguably be extended to a more broad term, as far as mastery over nature itself. He uses flowers that brings his enemies to sleep. That's not really something you can do off plain old wood. He fought against the Kyuubi and Madara, so we know that he has over-all amazing strength against overwhelming power.
Hashirama could heal without forming hand seals. ET Madara said that his medical jutsu outclassed even Tsunade's without her forehead seal. These two are the same people who stood out in the ninja world, and were thought of as legends. He should in term gain ALL of Yamato's feats and multiply them further. Yamato made a waterfall out of flat land. I highly doubt it is above Hashirama to make fissures, lakes or much much more. He can fuse into his life itself, much like Orochimaru's LAC, while sending out Wood Clones that are near impossible to pick out.
