8" away from a 103" ? Good lord, I can't stand sitting closer than 11 from my 60"...Yup, 4k is absolutely useless for me, at least when it comes to movies. for certain videogame genres, it could prove to be pretty darn amazing. Mario Kart 9(in 5 years) locked in at 4k, and sitting even closer to the screen would be pretty damn immersive.
11 feet from a 60" will certainly see the benefits of 4k over 1080p unless your eye sight is rather bad which if it is i'm sorry to hear.