The luggage set is gorgeous and seems sturdy so far. The wheels are very smooth to roll, open/close mechanism is precise and reassuring, and the compressor belts are useful and well positioned. No space is wasted also.

Now a few improvement points I'd like to suggest:

1) The handle is a bit bulky, with one boxy edge that makes it harder to slip a backpack / briefcase in. Also, when carrying two of them back to back, the two handles don't fit together well, and become very large to wrap my fingers around (and I have big hands). So, in summary, slimmer handles with round corners.

2) When extended, the telescopic handle does not hold position. Even without pressing the button, it can be pushed down. I'd prefer a lock mechanism that keeps it in place (fully extended) unless I press a button

3) For the large bag, you need to add a handle on the bottom side. Loading a 25kg large bag to a car, without a second handle to hold (e.g. where the wheels are) is cumbersome. It forced me to either get help or hold on the wheels or corners, where there's not a good grip.