the surface 4 has more hardware. I had a Surface Pro 3 and SP 4, hated both of them. They had fans that made a lot of noise, the systems got hot (even when running just a trial version of Artrage and would crash), it was a real pain. If that's what you want, you'll need more than a chip that can handle it, I'm sure the Ipad Pro would need a hardware redesign, which I think would make it less desirable in form and function. I could be wrong, not totally knowledged on the hardware, just know what the Options were on the Surface Pros I tried. I know they have the M processor which doesn't use a fan, but also know that the models with that don't have the processing power to handle big software, like the I5 and I7 processors could. I had the I3 SP3 and the I5 SP4 and the upgrade to the SP4 and the higher processor, didn't really make any difference in the problems I had. Such as loud fan noise, excessive heating up after minimal use (to the point I couldn't hold the tablet in my hands, too hot and uncomfortable), and crashing of certain art programs. Not to mention reading all the small drop down menus that came with some of the Art Programs, just wasn't User friendly on the small 13" SP display. I wasn't about to pay the price for the I7 Processor on the gamble that it may handle those problems better.
I think everyone that keeps saying that they want to see what OS X on an Ipad Pro would look or feel like, should go buy a Surface Pro 4 and try it, just to see how you like it and you can always return to the Microsoft Store before the return period is over. I really wanted to like it, but I left windows 7 as being the last time Windows was any good and the latter of their OS upgrades, including Windows 10, left a lot to be desired. Now I have a Mac and am happy, but I downgraded from Sierra, back to El Capitan, due to some Problems. I since am leary of upgrading my Mac now too. Definitely better than my windows experience though. Who knows, If you like the Surface Pros, it may be just what you're looking for instead of a Hybrid Ipad Pro. The stylus was decent, but I had severe lag with sound in programs as another problem. I didn't need a Hybrid, I was just looking for a Tablet, not a computer and tablet together. With Astropad, i can use for some of the Mac OS X Art Programs if I choose. All the rest I have my Mac. Just like typing quicker and easier on the Mac with the keyboard.
