One thing to be careful of (at least if cost is a constant consideration, as it is for most people) is to avoid getting hooked on Hz inflation. (This is also a problem if you have wildly varying refresh rates or resolution between monitors at home and at work, so less an issue for T2DB)
I have a friend, life long PC hobbyist, electrical engineer/programmer in school and now network admin fellow, who growing up always went for the high-end Hz-wise, in whatever form factor was relatively cutting edge (prosumer range).
He'd come and game at our place and shit on our monitors.
"Ouch. These monitors hurt my eyes."
He also used to kick our ass at everything (particularly Age of Empires II), the smug muthafucka.
But his complaint was legit from his perspective--he had got used to a more buttery experience.
So whither from that point? You can only go downhill--and your next monitor whatever the resolution will need to approximate that pricey refresh experience to give you the same ballpark/satisfactory response time ...
I went a different route with my last monitor purchase and overbought for need for sure, going with a 42" 4K LG monitor. This has probably locked me into a size/resolution trajectory where I'll have a hard time going smaller or going with anything less than 4K ...
Fortunately, though it's not quite the same as Moore's Law, monitors tend to increase in size and resolution at a pretty reliable rate with costs remaining relatively stable, AND high-end Hz/refresh rate seem to follow along, in their case generally managing to be among the most expensive in their size/resolution class.
All things being equal, I'd rather put that money into processing/memory/SSD, because ... we all use the computer for things other than gaming and who needs high refresh to type up a Word doc or browse the web.
Even more anecdotal side note: a large enough monitor finally convinced me to start flying the Little Bird more regularly because I felt like I could finally see ground targets from a safe distance. At 42" the breadth of the monitor also approximated cockpit in a more realistic way, filling peripheral vision in a pleasant manner.
Really, this just emphasizes the subjective nature of such a decision. There's probably a good buying guide somewhere that can prompt you to think through what you value in a display and decide via a point system, say, i.e. as rational a basis as possible ...
And that can be part of the fun. The planning.
Damn, this sounds a bit like a PSA.