TOO big does not work so well, as it requires too much head movement. Or requires sitting further away, which kind of defeats the purpose of a larger screen.
For computer use, a TV in the 40"-50" range works better. Get a 4K UHD model (3840x2160 pixels) and you have the equivalent of four 20"-25" HD (1920x1080) monitors. Makes it easy to use multiple windows at once, or just increase the overall font size so that I do not need my usual reading glasses. Look for a model with even lighting at low brightness or you'll eyes will tire quickly.
I use a 50", and find it is almost too big, as the upper part of the screen is a little too high for comfort. I either use smaller windows on the bottom, or have to lean back to read the top. It is kind of nice for reading the digital edition of the local newspaper, leaning back in the desk chair, feet up, with my morning coffee. I can easily read two facing pages, each of which is about 50% bigger than the print edition.