Bottom line - I like them, although I don't used them very much. Candle lanterns are very traditional - just the ticket for lighting our path as we pick up our alpenstocks and leave the hut for our predawn start up the Matterhorn. I generally like any appliance that provides both heat and light (like this forum).

The downside is that, where I live anyway, is that the candles melt and freeze up the mechanism very easily. This has always been a problem for me with all candles, not just UCOs. Hence they are not a very prominent part of my kit.

I think you are right about their light construction, but they will function with reasonable care, as long as the candles don't melt on you...