You decide wether you want to spend the money in a new shiny you don't need or not!!!
I have the late 2013 as well it's going to be fine for me for at least another year or two so I won't be getting a new one unless mine bite so the dust!!
In your own assessment, it is running fine and has no issues. I think you, too, know the answer in that case. It is just want and not a real need. If it was a real need, you'd have booked one first and then posted here about having booked it.