98% of the wood that I split with my Ultra I use the single wedge because I like to control the size and shape of the pieces. I only break out the 4-way when most of the rounds that I need to split are 8”-12” in diameter.
Thanks for commenting. From my experience, Walnut seasons faster than Oak. The bark seems to hold quite a bit of moisture, but the wood itself dries quite nicely.
I am also pretty particular about size of splits. Like you, I usually only use the 4-way when I have quite a pile of rounds in that 8"-12" range. I recently got a load of Oak and Hickory logs from a logger that were all on the small side (6"-12"). The 4-way worked awesome. I set it kind of high so that in most cases the two pieces on the top came out the right size, then I split the bottom two pieces one more time each. The 4-way definitely saved me time on that wood and it didn't create a crazy amount of scrap either.