I'm running 1280x960 as I type this. That image as posted is 1600 x 1200.
IMHO, width of a posted image should not exceed 800. Having to horizontally or vertically scroll a posted image ruins the images's effect.
I shoulda said that I started out at 1024. That ran for quite a while, then 1600 and now 1920.
I think the tablet runs 1280x800, so width =”800” seems more than fair.
Peeps should hold their smart phone sideways. Just sayin’.