As someone with essential tremors -which often comes with aging- I could not use any of the touch screens that were new 2 yrs ago. They either didn't respond, or skipped 2 or 3 pages or suddenly went somewhere else .... from a book page, I'd suddenly be back to the menu or in settings, etc.. Even the store clerks agreed that touch was not for me. I haven't tried more recent ones.
Also, the size of your hands are a consideration. From the tip of my middle finger to the base of my palm is just over 6"; with hand spread open, from tip of little finger to tip of thumb is 7½" . When holding a reader with one hand, having to move a thumb or finger causes me to lose all stability.
My clunky little ereader works fine for just reading books; it has both buttons and a slide bar to turn pages.
But, I did recently buy a 7" tablet with a touch screen and it does quite well for me, although the stylus works MUCH better than fingers. I don't plan to use it for reading - or only occasionally for short periods, like waiting for a Dr appt. If I need to do more than read, then it is extremely handy to toss in my purse and take along. I love my laptop, but no way does it fit in my purse or shoulder bag!
The case I have for the tablet has a keyboard which connects via usb and that is WAY better than the on-screen keyboard where I basically have to use the stylus and even a short note takes forever.
Do any of the touchscreen readers have a way to adjust the 'touch' sensitivity? If not, then I am another one that hopes buttons are here to stay on at least some basic models.