Yes, you should upgrade to a newer camera but not exactly to the newest technology, by new camera I mean the “new to you”
Most people now know that a camera doesn’t make you a better photographer, so you could spend over $100k USD and still take mundane photographs. What I want to tell you is that a better camera means one that you feel comfortable using and one that still brings that special feeling when you press the shutter and hear the click. One that simply feels like you are creating art instead of capturing 30 of the same mundane angle.
I started my photography career with film and a single manual SLR and two zooms. Now that I know a bit more, I wish I simply started with a prime lens but at the time people told me a zoom was my best option.
So, do you want to upgrade to latest and newest, do you want that vanguard Nikon D4s and think it will make you a top pro? No. You will still get the same angle, action and moment than if you used a Nikon D1.
Why should you upgrade to a “new to you” camera?
Because it makes you think, because it lets you slow down and enjoy it, because it helps you create art. Are you in for the money or for the art? Or for what reason are you in?
Finally, every photographer feels different in their own way, so what I say may be different than what you believe in. I believe that a Nikon D4s will help you take a great photograph, sharp, fast, and accurate. But ask, do you need the speed, bulk and weight just to take a photo of a standing building that doesn’t move more than 100000 mm per every thousand years?
Hope that helps to anyone out there.