Not sure you called it biased for I have own three different brand of tractors, pleased with each. My most recent purchase was my third Kubota, a
L6060. I have two that are right at 20 years old. Not perfect but very good machines. Still before buying my current one at least looked at every brand within 50 miles. LS, Kioti, Mahrinda, Yanmar along with JD and Kubota. The LS dealership was new with them but old dealership. Mahrinda can not keep a dealership here. Now down to used car dealership with no real shop. The LS just did not impress me. One that does not affect the machine other than I just don't like the blue of the LS nor NH. My nephew has a NH built by LS I think that has the issues of cracked fenders and weak steps. Strong tractor. Yanmar really impressed me but again new dealer with no real tractor experience and next dealership over 100 miles away. That and they stopped with their own dealers few years back.
You are looking for a machine to USE, right? It will get broken, need maintenance, filters if nothing else. Trees are the hardest material on tractors of anything I know. Even large limbs and stumps no tractor is built to stand up to them. Look at the tractors people really use in the woods. You just can not help it. So you will need support. Kutoba and JD yes have the largest network of dealers. Do they cost more, not sure but can say their price is higher. Price is only one aspect of cost.
I may well have bought a Yanmar had there been better dealer support. To me a dealership should have common parts in stock, they should have a mechanic or more, they should know their products, tractors should be their main business. I find it interesting with so many old establish tractor dealership who's brand has been pulled due to mergers or not being large enough to suit JD or Kubota these other brands are not able to find more dealerships. Nothing like a machine needing a $50 part no one has or no idea when they will. FYI, the Kubota I got three months ago have had to replace a turn signal and the grill wire in front of the hood. Tree limbs, using grapple to pile trash. Dealers did not have the grill wire in stock but within a week parts were in my hands.
BUILD YOU AT LEAST A GUARD FOR THE FRONT OF ANY TRACTOR USED WITH LOGGING DEBRIS. Also open bottoms.