They are very good. I ordered several different lights to decide what to use in my wife's office and while not the cheapest, their thoughtfulness and build quality proved to be the best. As a result, I installed 9 of these lights in a false ceiling. A room that used to have five 2" x 2" fluorescent lights, one track-mounted halogen light, and one Rando light. I reinforced each drop ceiling panel with liquid nails, nailed 1/8" thick fiberboard (MDF) to the back, and then drilled a 5.5" diameter hole all the way through. The headlights slide in and out of such a large opening easily, and the springs hold them in place with no wobble or gaps when you're done. (I had a brief incident where my 14-2 gauge wire was stiff enough that the bend pressed against the ceiling joist held the light at an odd angle. This was apparently corrected by simply bending the wire differently.) Connectors are easy to install and difficult to remove, which is great. The built-in "box" is the perfect size to connect in series. The entire room is now hooked up to a Lutron Diva dimmer, which works great.
Ceiling lamp Yeelight YLXD013-B, 50 W, number of lamps: 1 pcs., color: white
62 Review
Lamp LED Xiaomi Mi Smart LED Bulb Warm White (XMBGDP01YLK), E27, 8 W, 2700 K
26 Review
Lamp LED Xiaomi Mi Smart LED Bulb Essential (MJDPL01YL), E27, 9 W, 6500 K
113 Review
Lamp LED Yeelight Smart LED Bulb W3 (YLDP005), E27, A60, 8 W, 6500 K
47 Review