Cant speak about iPhone X, although a lot of people i work with do use the X. I carry a 7+ as my personal, and for work i currently have a 6S. I wanted to get an Android for work but we use Office 365 and the general experience with my work function and Android is very laggy, and has processing information issues. I am sure the issue is not specific to Android but moreso a problem with my company not knowing what theyre doing.
Being an Android fan for 3 years i jumped ship last year for a 7+, iOS just has been phone that "just works". My list of Androids in that 3 year period include Nexus 5, S6, G3, G4 and 6P...all had a slew of problems that drove me insane. My best experience was the 6P for its first 8 months until it started acting up (i think with release of 7.0/7.1). After all those problems i had, and the fact iOS has generally been very good to me (some very minor bugs), its hard for me to consider spending any money on an Android. I am sure the new Pixel phones are amazing overall but i have doubts biting the bullet. Plus my wife and all friends have iPhones, so iMessage just locks the deal.
what do i miss from Android? Google Assistant at OS level, Siri is very poor and doesnt fill the gap at all. And i miss my heptic feedback typing on keyboard. Otherwise, iOS does everything else fantastic.