I'm 24 hours into this switch from the Note 5, and I'm still mixed about whether I like the iPhone 6s+ more than the Note 5. I feel like iOS is much more polished and refined versus the Note 5. I didn't use touch wiz but Nova Prime launcher which helped the phone run much smoother. I miss the S Pen, wireless charging, fast charging, true dual screen multitasking and the camera...all of which I think separate the Note 5 from the iPhone. The one plus I've discovered so far is the battery life has been pretty good so far compared to my Note 5. Perhaps I need more time, but is it too early to say buyers remorse?!?!
Both are excellent phones and two of the very best on the market. It all comes down to which o/s you feel more comfortable with. Both have pros and cons.