V10 only has one rear camera foo. V20 has two. They're different beasts though. iP7+ has one normal lens and one telephoto (zoomed in) lens. It uses the two zoom levels to do some weird shit.
The V10 front cameras and V20 rear cameras have one normal camera and one wide angle (zoomed out) lens. So it can take wide-angle almost fisheye pics.
The iP7+ dual camera stuff is kinda cool but I honestly thing the wide angle is more useful. It also mentions that the iP7+ is bumped to 3gb. Bishpls, V10/V20 have 4gb.
If TMo gets the Pixel, I'll almost definitely pick it up. If not, I'll probably go V20. The V20 will have bamf cameras, removable battery, an sd slot, ir blaster, bigger screen, bamf DACs, etc. But the Pixel will be updated straight from Google, will have tons of ROM options, and will probably be cheaper.
BAMF features vs clean OS with fast updates and ROM options.