@Super:
The Logia type was only considered the strongest because of its atributes rather than its actual capabilites; the atribute that was 95% responsible for making the Logia type seem the strongest was intangibility.
However, we are in the New World. The ability to use haki is prominent to survival there. It also means that the main atribute that made the Logia type so attractive to anyone outside the New World is gone.
Unless your Logia can deal serious raw damage (i.e. magma or ice) is is almost worthless. Fire and Gas is so-so.
Smoke, fruit juice, candy, paper, electricity and snow either deals no real damage or have too many weaknesses. Some even have both.
The Paramecia abilities that can be trained to be used even better are a far stronger choice. So far, that would account for most of the abilites we have seen except for a handful (i.e. Bon Clay's ability can't really be trained at all). They are more useful/versatile and we have already seen dozens of cases of it. Luffy, Law, Issho, Doflamingo, Jozu, Whitebeard, etc, etc…those are just to name a few.
Zoans are arguably the most powerful Devil Fruits. Remember Kaido's DF army?
http://static3.wikia.nocookie.net/__cb20131013132713/onepiece/images/4/44/Kaido%27s_Artificial_Zoan_Army.png
A leopard user left Luffy so fucked up he couldn't even get up afterwards…and that is without using haki and Luffy having a rubber body…
Think of Luffy being punched by some of these guys (guys with the strength increment of an elephant, moose, bear, buffalo, gorilla, hippo, etc.) only with haki, hitting Luffy's real body…Luffy would instantly die.
The same goes for most other characters.
Nah Nah Nah. An individual strength is heavily dependent on their combat ability/skill. DF is just an extra boost. Logia still/will remain the most powerful DF, either in east blue or New world. Haki doesn't make Logias useless because competent Logias can choose to dissolve their bodies if the strike is Haki based. Although, elemental Logias are most powerful because of the damage ability they posses.
Zoan DFs is the most dependent on the user's combat ability. A user with zero combat strength is useless either they have Lion or Gorrilla DF. Zoans gain the extra attacking power and/or defensive power associated the animal they change to. Lucci wasn't hurting Luffy because he's a damm Leopard. He hurt Luffy because he's master level Rokushiki user. All his attacks were based on that fighting technique but they were amplified by the DF obviously.
Lastly, if any of those zoans even if it's Kaido attack Luffy with Haki, he won't die because he can now cloak himself with Haki as well.