I have some of the various splitting tools and while some are more capable than others, it seems the species of wood your splitting also makes a difference. I have the Fiskars X27 and X7. It works fairly well for what it is. Just don't hit it with anything metal or have it hit the ground/gravel/rocks or it will be damaged. I have the Ames red fiberglass wavy handled splitting axe, actually my second one, since I broke the first one. Must have been defective even though I had used it for several years. I broke it splitting some Residential Ash. The flair/wings could be less severe since it tends to only penetrate the wood so far especially if the wood is knotted or twisty gnarly. But I like it since it only weighs in at 4.5#. Then I have the Council 6# maul. It's not bad, but does need the head shape modified some. Sometimes I'll use it to drive a wedge, and sometimes it is the wedge. I also have a Collins Michigan single bit axe which I use for those stubborn pieces that need another inch or two taken off so they can fit in my stove. It cuts well. I also use it for cutting out tree stumps.
I tend to start with the lightest weight splitting axe and work my way up to the heavier maul, even the wedge and sledge. If the Fiskars fails after a half dozen attempts, I'll move on to the Ames. If the Ames fails, then I'll move on to the Council maul. If that fails, then comes the wedge and sledge. If all of those fail, then I'll drag out one of the chainsaws and noodle/rip that piece. That's usually after I've accumulated more than a few partial rounds I wasn't able to split by hand.
As for which one is the best? It depends on the wood I'm splitting. They all have characteristics for the job they do.
One thing I will never do is spend more than $40 on a splitting tool. It's a hunk of metal on a wood or fiberglass handle. Different designs perhaps, but then I was never into Designer Jeans over plain ole Wranglers or Levis. I usually spend less than $30 on any splitting tool, but I had to try the Fiskars due to the reviews, so I raised my limit to $40 since it was on sale on Amazon for $39.