Welcome. You will find a ton of comments on TBN pro and con any tractor. The right choice is the one that's right for you. And I suggest the strength of your dealer should have a lot to do with your choice.
But do shop around. For one thing, prices can and do vary.
I looked at JD and Kubota earlier this year for a tractor replacement. Both make good tractors. I think you mistyped the JD tractor in your post. I assume you meant a JD 3038e, which is comparable to the
L3800 in horsepower.
I made that comparison, and drove both tractors. I did not find the JD to be cheaper made. I found it every bit as well engineered and built as the Kubota. Prices for the two were very similar here, but better financing gave John Deere the distinct edge.
The deciding factors for me were the strength of the JD dealership, past experience with JD quality, and the comfort and design of the controls. The JD was considerable easier for me to operate, and the rocker foot pedals of the Kubota were very tiring even in a short trial... And totally beyond my wife's ability with her knee replacements.
I went with the JD 3038e and - with almost 50 hours on it now - I am delighted I did. But what works for me may not work for you. Good luck with your decision.