To be fair, you can't go wrong with either machine. It's been a while since I looked at one, but it could be argued the Grand-L might be a little ritzier in the overall feel. The Kubota I grew up with had excellent fit and finish, where I would say TYM is good. Just my opinion, of course, and not exactly an educated one lol.
I would be taking a good look at the dealers, looking over the assembled machines, talking to the service manager and mechanics. If I can, I'll talk to folks who have purchased from the dealer to see how their experience was, and how things have been post sale. Add to that, how long have they been around? How long have they been working with that brand?
If something does go wrong your dealership in the intermediary between you and Big Corporate, and Big Corporate wants to deny that warranty claim.