I had every iPhone since release up to the 4s. In between there were also a few Android smartphones which were then used as 2nd. After the 4s I decided for the HTC One, because it was a very good flagship and came close to the iPhone from the optics. That's why I discovered Beats Audio and had a hard time separating myself from it. For the iPhone 6s release I bought the Plus version, until last year for the X release and now for a few weeks the XS Max.
I'll probably never leave Apple again, because I work with a Mac at work and at home and also have my MacBook Pro on the road. The harmony between the devices is just perfect.