Derailleur replacement

Having had the derailleur that came with the bike, just literally all apart,had to decide on want to do. As I wanted to go to a 1 x 11 gear train, do I buy another cheap derailleur, or go for the SRAM Eagle GX 12 speed derailleur.
One event that helped, was the Black Friday sales.This, significantly reduced the price, so I purchased the SRAM derailleur. Which, arrived from Pushys.

In the meantime, I had been researching shifters. On forums, it was suggested that the shifter does not know how many gears it is moving. Well, this did not turn out correct. Having set up the new derailleur, and a replacement SRAM narrow 11 speed chain, and using the seven speed shifter on the bike, it would move the derailleur, but only half way through my existing 7 speed cassette.
Problem. To replace the shifter with the new SRAM NX 11 speed shifter, I would have to replace the brakes as well, as the brake lever and shifters on the bike, were a combined unit.
This meant getting out the new Shimano  XT M8000 hydraulic disc brake units. These come ready to install.

SRAM GX Eagle derailleur fitted.

Shimano brake lever and new SRAM NX shifter fitted.

I had purchased the brakes, both left and right systems earlier in the 2018, at more than half price.(Though I notes that the current new price has risen by quite a bit).
Once I had set up the shifter, I now had a 1 x 7 gear train. The 11 speed shifter moves the chain up and down the gears, but sometimes requires a double click up or down, or sometimes a single click: but it works, till I have the new wheels built and add in the new 11 speed cassette. (This may change, as SRAM now have released a 1 x 12 cassette, the NX Eagle, to fit a Shimano freehub).

New GX-1000 cranket set, 32 t, 175mm crank.

To achieve the 1 x system, the three speed from crank set was removed, and replaced with a SRAM GX 1000 crankset. This included removing the cassette bottom bracket, replaced with a SRAM GXP bottom bracket. One thing that I did notice: on the three speed front crankset that was removed, the middle chain ring, which is the one I used the most, the teeth were quite worn.
The reason for heading to a 1 x system was that I was mainly using a single chain ring at the front.
The SRAM 32 tooth has changed the dynamics of ride the bike completely. Even though I am running a temporary 1 x 7 I have not missed any of the other gears, and still have reasonable hill climb capacity.