The large blades are fine for battoning wood but they are no where near as efficient as the axe. My tusker (featured below) has an 8" blade and is 3/16" thick. As Scott pointed out at the diner on Monday before we left, the width of the blade can compensate for the thickness in giving it heft. My Tusker chopped and split and I still was able to shave hair. The large blade was useful but it cannot compete with an axe for the function of splitting and be anywhere near as easy to use. Could you get by with just a large knife? Yes, but you would have to work harder than with an axe. The axe's weight provides the advantage whereas the big blade requires more elbow grease to chop through the same amount of wood.
The woods provided us with a lot of blow downs and dead free-standing trees. It was a chopping paradise! We used large logs for main fuel and had a couple "white man fires" going. You couldn't even tell we used the area as so much wood was left untouched and ready for the next trip. We did fell some trees but they were dead free standing. Some were dropped for wood and others were dropped for safety reasons.
As for the mid-sized wetterlings, I know Joezilla had a long-handled hatchet and Scott had a full-size felling axe. Both were used hard and Scott is damn good with a swinging axe. In examining a couple of the Wetterlings on the trip, I noticed the grain alignment in the handle wasn't perfect or desirable. It is hit or miss with this company. Also, sometimes the grinds on the axe heads are uneven. Overall, these problems can be fixed and you get a decent axe for the money. I'll be doing a review on another brand of axe soon that is an excellent alternative to the Wetterlings, Snow and Nealy and Gransfors Bruks.
As for the full-sized Fiskars, I have one and I like it. It is, dollar for dollar, one of the best values in no nonsense axes out there. Mine has been used for a few years now and has never had a single issue. I wish the blade cover were better quality but other than that, it bites hard and is a good choice for a truck tool. Kind of heavy on the trail but worth it in camp. I'd suggest a full-sized axe for anyone learning axe craft as they are inherently safer than a hatchet. Plus for less than $40, you won't cry like you would if a $100+ Gransfors chipped on you. I am partial to axes and think you would be happy with one.