These are great things, but they turn on too early, when it is still too bright out, wasting energy. Right now, Sept 2ish, where I live (Ottawa area, Canada), they turn on about 45+ minutes before the sun goes down. Yes, you can see them, but these things are so low intensity that they are not useful until around when the sun goes down. But it means they are burning 45-60 minutes of power being on but being useless. As they often do not have enough juice to stay lit all night, this makes a difference.
Adding a way of altering the light level causing these little things turn on would increase their price slightly (which is one possible solution), so instead of that it would be nice if the manufacturers slightly reduced the light level triggering these things when they come on. Either way, it would be nice if they indicated at what intensity in candela they turned on, so consumers could select the appropriate solar lamp which turned on at the right light level.