Bought my B3350 Sept 2015. Regen occurs every 10 hours. Latest one did not complete after 3 hours. At dealer to reset computer. Dealer will not sell any more B3350s. He is recommends I trade it in because at altitude or in cold weather they cannot get the problem solved.
You may want to talk with another dealer -- my understanding, and what a dealer on here (Messicks) mentioned, is that Kubota has resolved the problem once and for all. I believe it was sometime in 2016 that the fix was implemented. It required replacing a small amount of DPF components, as well as computer and software changes.