There'a a lot to consider.
Engineeredlawns
From a quality standpoint, both Timberwolf and American as well as Iron and Oak are all "top notch" splitters. Speeco, Huskee and Northern Tool offer great value and performance for the buck.
But I think the choice of what splitter to buy and how to equip it really comes down to FOUR AREAS OF CONSIDERATION: 1. WHAT are you splitting - size of rounds and species, 2.WHY are you splitting - for resale, for your own use, for fireplace use, or OWB, 3.WHERE are you splitting - taking the splitter to the wood or thaking the wood to the splitter and 4.WHAT'S THE COST?
1. The size and species of WHAT you are splitting will determine features -things like the need for Horizontal vs. Horizontzl/Vertical model, as well as size of splitter in tons and stroke length or cycle times. Or wether you will equip your splitter with a lift for the really big rounds. Additionally, convenience features like a four or six-way head and outfeed table need to be considered.
2. WHY you are splitting (commercial or home use) will help determine the capacity of the splitter in cycle times to increase production as well the need for production oriented features like a four or six way head, and auto return valves, and outfeed tables etc.
3. WHERE you are splitting I think determines the need for wether or not a lift or horizontal/vertical splitter is needed. I may catch flak for this, but I feel if you take the splitter to the wood, i.e. where you fell the tree, then a lift or vertical splitting is handy to have. . . simply roll the large rounds to the splitter or lift and you're in business. HOWEVER - if you bring your wood to the splitter it would make sense to reduce the size of the large rounds first ripping in half or quarters with a saw -to minimize handling of heavy rounds, so the need for a lift or vertical splitting is diminished.
4. WHAT'S the cost? Obviously everyone wants the best splitter they can afford - and your own situation and buget will determine what's right for you.
Lots to think about - good luck in your choice and post some photos when you get your unit!