RK is a rebadged TYM and there has been a LOT of debate about the quality of their service people and whether or not they'll still be selling tractors in the future.
I almost went TYM instead of my kubota, basic numbers were that I could have gotten a 47hp TYM for the same price as my 26hp Kubota. One thing steered me away at early onset, was I heard he was great but the dealer pretty much worked out of his garage. I don't buy into the dealer being all to important, but having one near by for parts and for a potential fix did carry some weight for me. As for the tractor the TYM was nice, was the build quality as nice as my Kubota, no I dont think so, but still a nice tractor none the less.
I dont think TYM is going anywhere, they have been making tractor parts and tractors for other names for 40 years or so, it is just until recently they started branding their own machines. They own TYM, RK, Branson, and make some mahindras.