VP, I had the same dilemma, and I made the change, MS to iPad, and do not regret it.
Can't comment on the technicalities, but within the few differences there are work arounds or very helpful Ppruners.
Re keyboard, same concern about change to the screen. No problem, will power and practice, the difference quickly fades into the background, even with aged fumble fingers and poor eyesight.
In addition the screen keyboard alone has advantages when fully mobile, space, orientation, etc; anyway voice interaction comes next - I dislike it, but may have to persevere. Bluetooth to the hearing aid, but as yet no mind-reading to replace the frail voice for input.