I've owned two and run a third that belonged to a friend (cord-king). The big circle saw cuts faster for sure but you can't out run the splitter. Both machines have to wait for the splitter to finish the cycle before they can finish the cut (unless you're in 25-30" logs). I prefer the harvester chain for a couple reasons:
1) You can buy a roll of harvester chain made into loops for 4-$500. They last for weeks but if you hit something, you're a chain-change away from being back in business. It also takes half the kerf of a circle saw chopper.
2) The circle saw usually only needs maintenance every 500 cord or so but if you hit something, you're done until you get it fixed. I've also seen the teeth come off
The key to production for us is to keep a truck under the conveyer, Our Timberwolf is a little slower than my buddies' Cord King but we out produce him by having enough trucks to keep the processer humming.
Another factor is how well you can regulate the size of pieces coming through the wedge. People whine about irregularities, an auto centering wedge would be really nice. We tend to get a lot of kindling size pieces so we put a grizzly thing on the end of our conveyer which screens out about half of it.
Good luck, whatever you end up buying, you probably won't ever go back to a wood splitter. I call mine "The employee of the year".
