I used Textra on my LG G3, G2, and Nexus 4 and found it the best. I think I didn't like the stock app on the G3 because of the look of UI and I believe the text area was too small not enough real estate to see all you are typing before sending and not showing enough conversation on the screen.
But playing with the Note 7 I like the clean look of the UI and bubbles and the screen is so big I don't think I'll have a problem seeing enough text and conversation on the screen. So I'd like to try and stick with the stock app. If not then most likely Textra. But I am kinda tired of the Material Design look.