Yet again, someone buying and returning these things like it's a lending library. On every level, morally, environmentally, intellectually, and economically it is just wrong. There are dozens of websites (not least Apple's own!) that show you pictures, give you the specs, talk you through what all these specs actually mean.... Is it so hard to do a bit of research and then think about it, rather than buying on impulse?
I mean, muppet thought it is, I've measured across on my iMac to see exactly the difference between 14.2 and 16.2 inches and what you can fit into them. I've even got a can or two from the cupboard to recreate that extra weight to help me decide what I want! Stupid and embarrassing to reveal this to the world, but much smarter than messing apple and other customers wanting an in demand product, around.
You certainly made very good points here but in fairness that practice of try and return no questions asked is pushed by Apple staff on the phone and in retail all the time. Customers take them up on it.