I've never felt the need to "give up" on Sony, frankly.
I like the heft of the various readers in different ways, (and I've got 'em all from the 3/650 gen on, T3 coming) and although I prefer the ally X50s - a superb bit of engineering of looks, function and feel - the later plastic jobs are great machines. I much prefer them to the KW I got as an experiment - I do like the lit screen in some situations, but would prefer it as an on/off option.
And naturally I do not speak of the software, which is just too much hassle to bother with !
I'm a Calibre and Alf user, and will ever be thus, so I have no restrictions on source etc.... and am not fussed about wifi - I never have the desperate need/desire to get a book IMMEDIATELY.
I just park 'em in me Calibre bookshelves and get round to them eventually.
Mind you, I won't be able to do anything about them giving up on me, I s'pose .....