Easy to install, no delay in start up, the bulb comes on with no flickering. Nicer to have the bulb in an overhead fluorescent fixture than as an lamp on a desk. My birbs are happier now and their feathers have perked up again.
They are a direct replacement for the halogens in my airstream. Old bulbs were 40 lux - these are 80 lux with the added benefit of almost no heat. They are brighter than the old lights, but not so bright they look like street lights.
After installing 4 the bulbs start to flicker. They flicker like crazy once you have installed them in both bays. This is product that has issues flickering and won't stay on.