I am well over the hill, my eyesight is going south, and I could use a 13-15 inch iPad (a Maxi?).
Actually, I had bought an iPad 2 a year ago, but web browsing strained my eyes too much with a 10' screen, so I handed it down to my niece.
The point is, I stay online a lot, but rather that sitting at a desk or using a laptop that, with a 9:16 non-pivot screen, is a horrible internet experience, I could lounge on my sofa with a tablet, provided its screen is big enough to be readable.
No big dpi count is needed, 2048 by 1536 will do nicely. Basically, it could use regular iPad chipset, only with a larger screen and battery.