I have a SON28 and run a mudguard-mounted B&M Seculight off it as well as the front light.
It's lovely to know the light's always there (until it falls off).
The main problem I've encountered is when I've just parked my bike and the standlight's still shining and another cyclist thinks he's doing me a favour by walking over and trying to switch it off using a non-existent switch.
Ha. Yes. I've actually run into problems trying to get on trains and platform staff being funny about the standlight on my rear B&M which isn't switch off-able.
I have a SON28 and run a mudguard-mounted B&M Seculight off it as well as the front light.
It's lovely to know the light's always there (until it falls off).
The main problem I've encountered is when I've just parked my bike and the standlight's still shining and another cyclist thinks he's doing me a favour by walking over and trying to switch it off using a non-existent switch.