Yep. Now add some buttons while viewing an A4 paper. On an iPad they fit nicely next to where you're holding it, on a Surface you either have to put them in an awkward position, shrink the content or have them it popup in some generally non discoverable gesture.
"The aspect ratio of A4, 1:1.414 is near the average of 1.5 for 2:3 and 1.333 for 3:4. US Letter is 1.294.
Still Surface Pro 3 aspect is better than 16:9 (1.78) at least.