I have N900 and for about a month LG G4 and I remained using N900. Without QWERTY it is unusable, to write TODO lists, notes, even to write URLs, those on-screen keyboards take forever to type together with many typos, and it is just inconvenient. When I need to do anything with the phone I SSH to N900 but I haven't yet found anything similar in Android. There are some chroot Linuxes but I could not get sshd running there. IIRC I got sshd working on Android itself but the shell is unusable there (or maybe I even did not get sshd working there, not sure now).