80 PPI is still very high.
It comes down to your visual acuity and viewing distance. 2-3 feet away and you shouldn't have any problems. I don't know where people get this from, but on my 32" 1920x1080, I don't see the pixel structure (people say pixels which is wrong) even from 2 feet away, and my vision is waaay above average,.
With that said, a higher resolution on a 27" is considered to be the sweet spot, because from a typical viewing distance which is 3 feet, you have more screen real estate, and you have more information in the signal. You get 100 PPI.
Unfortunately people confuse less detail for being able to see the pixel structure, I really have no idea where they get that from, I have yet to see proof of their ridiculous...