I just finished setting up my 4k monitor, and train sim looks AMAZING. I love how smooth everything looks, and it runs pretty well too, 60 fps on some routes, 40 on most, 25-30 on some of the more detailed routes. I've extremely satisfied with this monitor!
Nice purchase. It does look good in 4k. I don't have a 4k monitor but I do have a 55" 4k UHD TV and TS looks great on that.
So?.... I don't care... Jeesh jealousy's an ugly beast.. Enjoy your jaggie-less train simming. (cries in 1080p)
I don't know what your budget for one would be, Reef, but you can get decent ones for a few hundred. I mentioned elsewhere the one I got was £300, but Amazon offered it in five monthly payments (which equalled the cost - no added interest), so it became more affordable at £60 a month.
I've got a 43 inch 4k TV but it still shows the shimmering on the overheads even at 3x2 msaa. Probably down to size of the screen, you can see things more clearly which isn't always a good thing
Just be aware that although TVs might be cheaper, there are issues such as lag and chroma subsampling that can affect productivity: https://www.rtings.com/tv/learn/chroma-subsampling https://www.displayninja.com/chroma-subsampling/