So, then Sharkey what's your guesstimation on who had more power and why Johnson wasn't able to Knock Willard down once over the course of 26 rounds hiting him with hard shots repeatedly. Fights like the Jefferies come to find in saying it seems Johnson had good power yet couldn't faze Willard yet Dempsey destroyed him with one punch essentially. Also, I've never seen there statement by Jess about Dempsey because I always thought he made statements claiming he thought dempsey's gloves were loaded. Granted fighters fighting a common opponent doesn't tell a whole story to determine anything but it seems you certainly can make inferences based on it that you wouldn't be able to make had they not fought a common foe.
They both had good power, but if you're asking for my opinion on who hit the harder, I defer to Willard's statement saying that "Dempsey was the hardest puncher" he ever faced, and also Fireman Flynn's statements from the early 1920's when he stated that Dempsey gave him the "hardest punch he ever recieved" (Flynn is also quoted saying Langford hit him the hardest, but seeing as how I don't know the timeline of when that was given, that may have been previous to fighting Dempsey...the Dempsey reference he made was most definately after fighting both).
Both Willard & Flynn fought both of them (the only common opponents?), and both picked Dempsey as the harder puncher, which is good enough for me.
It's also worth noting that Willard was notorious for being a slow starter and coming on later in the majority of his most importatnt fights (Johnson, McCarty, Morris, Moran, etc., and even to an extent, Gunboat Smith, where the reports state that Willard started doing his best work from the 4th & 5th rounds on, before Smith reportedly made a late charge himself), so considering the pace Johnson and Dempsey fought Willard at (Johnson fought him fairly slow, with short flurries, clinching, rinse and repeat), some element of Dempsey's early success may have been exploiting a little bit of a Willard weakness who usually needed a few rounds to warm to the task. Couple that with career stages, punching power and everything else, it might help explain your question a little bit more.
And after being initially complementary of Dempsey right after the fight and continuing to do so for some time, Willard didn't start his "loaded glove" theory until a few years after the fight when he tried making a comeback in 1922, and that may have been used as a way of trying to force a wanted rematch with Dempsey, much like George Foreman stated in the immediate aftermath of Zaire that he hoped his complaints (about being drugged, the ropes, etc.) would at least entice Ali into giving him a rematch.
If Willard wanted to complain about Dempsey having plaster of paris on his gloves or having them loaded, he had every opportunity to do so immediately after shaking Dempsey's taped up & gloveless hands just before the fight, which is shown on the full available footage of the fight (as it shows the gloves being taken out of the boxes, and then put on in ring, as was the custom during those days).