I have a 27" and I use it in conjunction with mouse\keyboard support. I FIND that there are somethings a mouse and keyboard are just faster at like entering track names, or fine detail moves. I don't know about 4k or 'its too big' - the size of the widgits on my screen is perfect for my finger \ hand size. To each his or her own certainly.
I have mine at a higher angle than low and flat - between 45 and 90 degrees. I change its position if I am recording an acoustic instrument myself and multi mic'ing. Its really sweet to have my back to the 'mix area', move the screen off to my left on a little portable desk, and use my left hand to 'push' the record button with. Frees my hand from keyboard or mouse clicks and positions my freting hand at neck height only inches away.
If you do end up using a higher angle on the display, depending on the size of your work area, you may want to consider monitor stands if you do not have them. At 27 inches, my monitor pair on desk has a speaker separation of about 32 inches. I like to make sure the speaker projection is not reflected by the back of the monitor. When the monitors were at the back of my small desk, and using the triangle equilateral distance standard, the listening sweet spot was a full and uncomfortable extended arm length from the mouse/keyboard.
As a side note, I use another monitor like this for live sound and its great to mix, eq and to manage all the VST's we use live. Good luck on finding the right monitor!