Sempervivum troughs

The 3 troughs I made last summer (2013), strategically placed outside my kitchen window and artistically decorated with Sempervivums, and a couple other things (Sedum and Thlapsi stylosum) are doing GREAT!
After reading how sturdy these troughs are, I made them. After making them, I read how sensitive they could be 'cause of freezing, etc.
NOW... what am I to believe. A lot depends on the recipe ingredients. I am sure I didn't really mix only goodies together.
We will see! So far, the first winter (kind of a mild one!) has not damaged the troughs and the plants in them seem happy.
Look!