I haven't had a tablet of any other brand so I can't compare. I can say what I like about iPad Pro, though.
A big part is the apps and the ecosystem that you get with other Apple products. It is almost seamless. Start something on the iPhone on the bus, continue on an iPad or Mac when you arrive at the office. I also like the relatively clutter-free environment that iOS offers. Or the ”limitations”, that Android users probably would call it. :-)
One thing I find fascinating about Apple products, compared to Android, is that iOS users make up such a big part online. On Savvitys sister community, iFokus, 65 percent of the visitors use iOS. That's not anywhere near Apples market share.
I like apple products because of iMessage, its integrated with your normal texts so no messy apps like whatsapp clogging up my home screen. iMessage/free messaging services are a priority for because my boyfriend has spent the past three years in Ameria studying. Avoiding big monthly phone bills has been a great plus.