I bought the T Rex 3.0 as my first 3D printer a couple of months ago and have printed about 100 prints with PLA with great success and lately with PETG. The PETG began adhering too strongly to the PEI surface so I need to work on managing the surface better.
The printer is extremely accurate through the calibration process and prints. It printed the benchy file it came with beautifully with no strings and only a couple of tiny bumps on the hull.
The company is very responsive with communication. I just received the latest upgrade kit that adds the TMC2209 steppers and removable flex plate surfaces that are standard with the latest version.
IDEX is a harder to manage and less supported which is why I found this post. I always set the appropriate IDEX mode now if I plan to do anything with the second extruder to prevent head crashes (learned behavior
The T Rex is such a big printer and as close to industrial quality for the price that you are really getting two large durable printers in one. I am printing scale model wind turbine parts that take 10 to 15 hours each and printing two at a time. Quality components, large size and dual extruders are why I chose it.