How much better is D7100 over D5500 really?

[darkblue-x]

What type of display does your desktop have? Twisted Nematic (TN), In-Plane Switching (IPS), Parallel Vertical Alignment (PVA)?
Is it the same type display that your phone has?
Are they both calibrated to the same ambient light falling on them each time you view photos?

Is the browser you use 'color aware'?
Color Management & Quality Output: Working with Color from Camera to Display to Print: (The Digital Imaging Masters Series)

How to Calibrate Your Monitor for Photography

IPS Monitor

I'll try and find which my phone is, but I believe it's just the photo that becomes different (either that or my laptop is the one that is different).

I extract as sRGB only so, I'm not sure if I should change that...

 

[KmH]

No. It's not just your photo that becomes different.
It's because the photo is displayed on different devices.
They have different operating systems and different color management setting/strategies.
Even if both are IPS displays each likely uses a different type of back light.

You might get your phone and your display close to being the same, but that's the best you can hope for.
As far as looking at your photos on other devices, the devices of others, the variety of apps and browsers - there is no way to have them all the same.

 

[dunfly]

I have been trying to convince myself to upgrade from my 5 series to a 7 series or even the D500 for a while. I have looked in depth at all the great features I would get. Then, I looked at the images I have been taking, the type of photography I do and the settings I use. In my situation, close to 99% of what I shoot would never need the advanced features, plus my 5 series is lighter (for travel), smaller and has an articulating screen. I guess what I am saying is to take a critical look at how you are using the camera and then see if you will actually be using the additional features. In my case, the added features of the 7 series of D500 do not outweigh the size and articulating screen of the 5 series.