I tried different degree of light: no need to put it up because I find the excessive brightness. A good compromise would be to put it on the 6th level (levels ranging from 1 to 10). Do not have direct radio clock directly to you (as any alarm clock) because numbers alone can wake you up.
I liked the atmosphere light therapy that really wakes you gently. It is suitable for those who are light sleepers than those (like my husband) who have a deep sleep - for once and for his people there, the 10 level may be necessary.
Noise level, I highly appreciated this awakening to drill-like and small birds I prefer to "tuttt" deafening alarm clock. I also tested the sound of the radio, I have not had sizzling.
Regarding the brightness, it is easy to level 10 so that it serves to wake floodlight. I read with a headlamp but I could use this extra lamp.
In short, the light alarm clock is very good and will be appreciated by users who want a gentle awakening.