Underrated picture for sure, you moved long way since you started, your composition is getting better and better. I won't worry about moving to the 6s, here you can never satisfy all the gang all the time, even after you move to the 6s you will find some 4s pops up every now and then. My advice is not to evaluate your photography skills based on the rating in here, you wont be doing your self justice if you don that.
I rated this picture 8 while it was in the challenger,
Best of luck,