That's great feedback and good to hear that Intel iGPU is working well with HWA. The latest iGPU I have to work with is on the i7-4790K (iGPU HD 4600), and I haven't gotten around to testing it. I'm planning on ordering a new i7-7700 (iGPU HD 630) system this week, so would be interesting to test both them out and compare. Maybe it depends on the MB, but what's the port situation for you if you want two displays? I know you said you don't need fancy graphics, but just for comparison, what if you do turn on shadows + ambient shadows in a consistent shaded view, what's the performance like then with the iGPU? "Realistic" view + shadows?
The GTX 1050/1050Ti is a no-brainer for a $100 - $150 GPU that will be perfectly adequate (even with all the eye-candy turned on) for the majority of users on SD displays. It's roughly equivalent to the M2000 (which was a giant step up from the previous Quadro 2000 series).
We're moving to dual UHD (4K) displays, and that's where a beefier GPU is definitely needed (in my experience so far). We're still trying to find the sweet spot if that's the GTX 1050 or GTX 1060 or GTX 1070. This stuff is also very relative and subjective... I've seen performance that some people think is perfectly fine that personally would drive me bonkers.