Most people that are getting the plus did you previously own a 32gb or 64gb to justify paying the extra?
I settled on the 6 which I believe is £10 cheaper in the uk was than the 5s but still £40 more than it was a few years back.
Most I see go for the plus 64gb which is almost £700 or something which seems very expensive if going sim free.
I'm going from a 64GB 5 to a 128GB 6 (not Plus), and it's the same price as I paid two years ago, three years ago, four years ago,... The Plus would only be $100 more, which isn't bad, considering the camera and perks. It's just too damn big for me.
But if you're in the rhythm of (and can plan ahead for) selling/buying/selling/buying, a $100 jump isn't too bad, IMO.