They are very very hard to set up. I'm pretty good at setting cubes up and making them perform well, but Dayan cubes take a massive amount of time and effort to make perfect. Breaking in takes thousands and thousands of solves, even thick lube (traxxas 50k) dries quickly so you have to relube often (I want to try weight 8 to see if it lasts longer), modding is almost necessary (48 point edge mod on guhong/zhanchi) to make the cube smooth (this takes a long time), and the cubes can pop even on perfect tensions. The guhong and zhanchi can be very good specifically for roux once theyre set up. Theyre fast, stable, and blocky so you won't be misaligning sides during LSE or second block (this is a problem on cubes like the yuexiao, GTS, gans, etc). The thunderclap is just better in every aspect. It is less blocky and more bubbly, but it is still stable enough for roux. The set up is very easy: 200 solves, overlube core and pieces with 50k, medium/tight tensions, break in.