TCL TV vs Which Roku box?

This is not a problem but a sort-of technical question.

I have a TCL 43" Class 4-Series 4K UHD HDR Roku Smart TV - 43S431 that I bought at Walmart about 16 months ago. It has behaved flawlessly; no complaints. In fact, its performance (speed at loading streaming channels) is considerably better than my older Roku (v2) boxes connected to other non-smart TVs.

And this is my question: Would a new Ultra or UltraLT provide the same performance as the TCL TV? As there don't seem to be detailed specs regarding RAM, storage, processor, etc. that would permit such a comparison, perhaps there are kind readers of this post who do own both a TCL Roku TV and a Roku Ultra and might provide at least a seat of the pants comparison?

Thanks very much and a Merry Christmas to all!

Barry