I always use shimano, some times with Sram Attack shifters, other with grip shift but since dual release, always simano and that is why in one of my last creations I went Sram with the XX1 eagle 12 speed.
The first I notice is that I like and miss a lot the dual release shifter. And how cheap the XX1 shifter feels. It is a XX1, but it really is a GX that cost a lot of money because has one part in carbon that feels like plastic. The internals are the same. Price not justified.
The rear derailleur ....it weights a ton, much more than a simple and modern alivio. It is a bit bulky and has a tendency to have cratches. With only one month it has some scratches so I bought annother one and the carbon parts are not perfect, has some porosity.
I don´t like the modern bulky derailleurs so my last built was built in Shimano again but 10 speed XTR985 and it is so nice ...
I remember that many years ago they invented the sadow tech etc etc to avoid bulky RD and now what are they doing, they reinforcer them and invented the UHD ... and they weigh more and more ... and they are ruining the bike industry with all that theorically magic tech that goes to no were because all we see in youtube is not what we do in real life, I don´t need a bicycle capable to go down in a Red bull rampage and rated as XCO with 66º head angle, I dont need press fit, DUB, UHD, 1.5 head tubes, 820mm handlebars, plus or fat tires, a motor and a big battery, a electronic dropper post, a electronic RD, a electronic FD, 2-3 different chargers to charge all the stuff in the bicycle (add day light and GPS) etc etc etc etc. How a shop will have stock of everything ... they simply can´t and If I have to wait for something it is more easy to buy online and not to wait a queue in a shop, explain what I need, check if they have stock, wait some days, go to the shop, wait the queue, and ... pay more.
I´m out of all, I only whant to ride my bicycle.