I bought a Yuxin Blue 4x4 a week ago, and it is terrible. I've swapped out the springs for thunderclap ones, and that made a slight difference. I've messed around with the tensions too. Even when it's super tight/loose it still catches a ton.
I'm usually pretty good a setting up my cubes, but this one just won't cooperate.
The turning of the inner layers in particular is awful, exceptionally locky and catchy to the point where it is unsuable. For refernce, I can do a Jperm in about .7 seconds on a 3x3, 1.5 seconds on my main 4x4 (old yuxin) and 7.5 seconds on the Blue, as if they were 2x2s. Jperm takes about 3 seconds using the outer layers on the Blue.
I watched a couple of unboxings, to see other people blues out of the box, and their's function much better than mine.
Is this a good/bad batch thing, is it because of flash, Blues are really unusable otb, or what?