The driver is working fine and arrived pretty fast. One important thing about it is, that the driver chip itself on the backside of the board gets the warmest (the MOSFETs themselves stay cold), at least as long, as you're using them below 1A of current. The driver itself is NOT cooled by the provided heatsink, as they are just cooling the MOSFETs which are higher than the thermal pad of the driver! Thus from time to time the driver is turning off in my 3D printer, if there's not an additional fan directed to the driver boards. So, if you plan to use it with less than 1A, like usually in a 3D printer for instance, then the MOSFETs stay cold. So it would make sense to use smaller heatsinks, which are cooling the flatter driver chip in the middle instead then!
Working flawlessly as expected ! Fast shipping thanks!