I love these panels!  We recently moved into a new home with beautiful windows in master bedroom, but because it faces east, we were being woken up at the crack of dawn!  We added these panels and our room stays dark and we can sleep until the alarm goes off.  I did not have to buy new curtains, just added these.  They work perfectly.  I strongly advise anyone to get them!

Pros: Perfect! Works great!
Cons: None