All day, every day. Type with it, dial with it, scroll with it, use the calculator with it, write, draw, annotate, select/copy/paste text and images, "smart" select, magnify, etc., etc.
But most importantly I use the original S Note/Action Memo app. I think that's a big divide in S Pen users as well. For those who came to the Note series with the N7 or 8 and unfortunately were introduced to Samsung Notes, it's hard to imagine the myriad features and functions of S Note/Action Memo. Even some who did use it in older Notes used only its basic features.
Then there's also the fact that I really miss my BlackBerry physical keyboards, and typing on a touch screen sucked after that for me. My first Android was the Note 3 (and all Notes since), originally so I could use the pen to type/swype. Just exploded from there