I agree....I order a couple of each filter from tractor smart. The prices are good and the delivery is a few days.
I thought about maybe changing to fram or some other brand but after thinking about the purchase price of the tractor I decided to stay with kubota. Also, if there is a warranty problem and they can blame it on a filter then you could really loose!
I take the same approach for my cars, generator, and outboard. I buy the branded filters and the best oil.....