Oh, you know I've given you specifics many times. They must just not apply to you.
For me, I still travel with my iPad even though I have a Surface Pro for several reasons. Primary is the battery life. I can take an all-week business trip to Europe, use the iPad extensively on the plane, in the lounges, or during in-between times waiting at hotels, etc. like I would pick up a book. I load it up with all of my magazine subscriptions so that I have plenty to read even when I don't have Internet access, and it will last me the entire trip without me needing to charge it or to even have to think about it. The Surface won't last me the flight over there, even using it in that mode, nor is it nearly as comfortable to use in those situations. It still feels like using a computer.
At home I use the iPad extensively as my music control system, streaming to wirelessly connected speakers. It can do this reliably and uses virtually no battery life to do so. The Surface
can't do this on battery because as soon as the screen shuts off, after just a few minutes, the music stops. There are only a handful of apps, none of them ones I want to use, that can continue to stream in the background. I do the same with the iPad and streaming video. I have an iMac that acts as the home server where content gets downloaded, and using Air Video the iPad makes a fantastic remote to stream any video type to my tv flawlessly. I've tried the wireless mirroring on Windows and it is clunky and often unreliable.
In general our iPad just sits on the kitchen counter as an appliance always ready for someone to pick it up for any of the above activities, to video chat, to look something up, to show someone a picture from our albums, to reference a recipe. It's rarely on the charger, and it's always ready to use. I don't get the same reliability from my Surface - and many of the programs that are perfectly fine to use when you have the keyboard attached are suddenly a lot less useful when you have dough-covered hands, and need to try and hit that tiny touch target.
This is why I'm ok with iOS and the app ecosystem - it means that battery life and stability are pretty much guaranteed - and that I am probably going to get an excellent touch UI at the same time. With Windows I may have the programs at my disposal to do most any of the same things - but there is no guarantee of battery life nor of a good UI. I'm somewhat of the opinion that Microsoft is going to have to start limiting what programs and processes can do in the background even on the desktop side if they are ever going to get battery life under control. Apple, with iOS, doesn't have this worry, because it's baked in as a fundamental of the operating system.